feat: patch chrono

javascript-engine/external/chrono/src/date.rs

@@ -0,0 +1,645 @@
+// This is a part of Chrono.
+// See README.md and LICENSE.txt for details.
+
+//! ISO 8601 calendar date with time zone.
+#![allow(deprecated)]
+
+#[cfg(any(feature = "alloc", feature = "std", test))]
+use core::borrow::Borrow;
+use core::cmp::Ordering;
+use core::ops::{Add, AddAssign, Sub, SubAssign};
+use core::{fmt, hash};
+
+#[cfg(feature = "rkyv")]
+use rkyv::{Archive, Deserialize, Serialize};
+
+#[cfg(feature = "unstable-locales")]
+use crate::format::Locale;
+#[cfg(any(feature = "alloc", feature = "std", test))]
+use crate::format::{DelayedFormat, Item, StrftimeItems};
+use crate::naive::{IsoWeek, NaiveDate, NaiveTime};
+use crate::offset::{TimeZone, Utc};
+use crate::oldtime::Duration as OldDuration;
+use crate::DateTime;
+use crate::{Datelike, Weekday};
+
+/// ISO 8601 calendar date with time zone.
+///
+/// You almost certainly want to be using a [`NaiveDate`] instead of this type.
+///
+/// This type primarily exists to aid in the construction of DateTimes that
+/// have a timezone by way of the [`TimeZone`] datelike constructors (e.g.
+/// [`TimeZone::ymd`]).
+///
+/// This type should be considered ambiguous at best, due to the inherent lack
+/// of precision required for the time zone resolution.
+///
+/// There are some guarantees on the usage of `Date<Tz>`:
+///
+/// - If properly constructed via [`TimeZone::ymd`] and others without an error,
+///   the corresponding local date should exist for at least a moment.
+///   (It may still have a gap from the offset changes.)
+///
+/// - The `TimeZone` is free to assign *any* [`Offset`](crate::offset::Offset) to the
+///   local date, as long as that offset did occur in given day.
+///
+///   For example, if `2015-03-08T01:59-08:00` is followed by `2015-03-08T03:00-07:00`,
+///   it may produce either `2015-03-08-08:00` or `2015-03-08-07:00`
+///   but *not* `2015-03-08+00:00` and others.
+///
+/// - Once constructed as a full `DateTime`, [`DateTime::date`] and other associated
+///   methods should return those for the original `Date`. For example, if `dt =
+///   tz.ymd_opt(y,m,d).unwrap().hms(h,n,s)` were valid, `dt.date() == tz.ymd_opt(y,m,d).unwrap()`.
+///
+/// - The date is timezone-agnostic up to one day (i.e. practically always),
+///   so the local date and UTC date should be equal for most cases
+///   even though the raw calculation between `NaiveDate` and `Duration` may not.
+#[deprecated(since = "0.4.23", note = "Use `NaiveDate` or `DateTime<Tz>` instead")]
+#[derive(Clone)]
+#[cfg_attr(feature = "rkyv", derive(Archive, Deserialize, Serialize))]
+pub struct Date<Tz: TimeZone> {
+    date: NaiveDate,
+    offset: Tz::Offset,
+}
+
+/// The minimum possible `Date`.
+#[allow(deprecated)]
+#[deprecated(since = "0.4.20", note = "Use Date::MIN_UTC instead")]
+pub const MIN_DATE: Date<Utc> = Date::<Utc>::MIN_UTC;
+/// The maximum possible `Date`.
+#[allow(deprecated)]
+#[deprecated(since = "0.4.20", note = "Use Date::MAX_UTC instead")]
+pub const MAX_DATE: Date<Utc> = Date::<Utc>::MAX_UTC;
+
+impl<Tz: TimeZone> Date<Tz> {
+    /// Makes a new `Date` with given *UTC* date and offset.
+    /// The local date should be constructed via the `TimeZone` trait.
+    //
+    // note: this constructor is purposely not named to `new` to discourage the direct usage.
+    #[inline]
+    pub fn from_utc(date: NaiveDate, offset: Tz::Offset) -> Date<Tz> {
+        Date { date, offset }
+    }
+
+    /// Makes a new `DateTime` from the current date and given `NaiveTime`.
+    /// The offset in the current date is preserved.
+    ///
+    /// Panics on invalid datetime.
+    #[inline]
+    pub fn and_time(&self, time: NaiveTime) -> Option<DateTime<Tz>> {
+        let localdt = self.naive_local().and_time(time);
+        self.timezone().from_local_datetime(&localdt).single()
+    }
+
+    /// Makes a new `DateTime` from the current date, hour, minute and second.
+    /// The offset in the current date is preserved.
+    ///
+    /// Panics on invalid hour, minute and/or second.
+    #[deprecated(since = "0.4.23", note = "Use and_hms_opt() instead")]
+    #[inline]
+    pub fn and_hms(&self, hour: u32, min: u32, sec: u32) -> DateTime<Tz> {
+        self.and_hms_opt(hour, min, sec).expect("invalid time")
+    }
+
+    /// Makes a new `DateTime` from the current date, hour, minute and second.
+    /// The offset in the current date is preserved.
+    ///
+    /// Returns `None` on invalid hour, minute and/or second.
+    #[inline]
+    pub fn and_hms_opt(&self, hour: u32, min: u32, sec: u32) -> Option<DateTime<Tz>> {
+        NaiveTime::from_hms_opt(hour, min, sec).and_then(|time| self.and_time(time))
+    }
+
+    /// Makes a new `DateTime` from the current date, hour, minute, second and millisecond.
+    /// The millisecond part can exceed 1,000 in order to represent the leap second.
+    /// The offset in the current date is preserved.
+    ///
+    /// Panics on invalid hour, minute, second and/or millisecond.
+    #[deprecated(since = "0.4.23", note = "Use and_hms_milli_opt() instead")]
+    #[inline]
+    pub fn and_hms_milli(&self, hour: u32, min: u32, sec: u32, milli: u32) -> DateTime<Tz> {
+        self.and_hms_milli_opt(hour, min, sec, milli).expect("invalid time")
+    }
+
+    /// Makes a new `DateTime` from the current date, hour, minute, second and millisecond.
+    /// The millisecond part can exceed 1,000 in order to represent the leap second.
+    /// The offset in the current date is preserved.
+    ///
+    /// Returns `None` on invalid hour, minute, second and/or millisecond.
+    #[inline]
+    pub fn and_hms_milli_opt(
+        &self,
+        hour: u32,
+        min: u32,
+        sec: u32,
+        milli: u32,
+    ) -> Option<DateTime<Tz>> {
+        NaiveTime::from_hms_milli_opt(hour, min, sec, milli).and_then(|time| self.and_time(time))
+    }
+
+    /// Makes a new `DateTime` from the current date, hour, minute, second and microsecond.
+    /// The microsecond part can exceed 1,000,000 in order to represent the leap second.
+    /// The offset in the current date is preserved.
+    ///
+    /// Panics on invalid hour, minute, second and/or microsecond.
+    #[deprecated(since = "0.4.23", note = "Use and_hms_micro_opt() instead")]
+    #[inline]
+    pub fn and_hms_micro(&self, hour: u32, min: u32, sec: u32, micro: u32) -> DateTime<Tz> {
+        self.and_hms_micro_opt(hour, min, sec, micro).expect("invalid time")
+    }
+
+    /// Makes a new `DateTime` from the current date, hour, minute, second and microsecond.
+    /// The microsecond part can exceed 1,000,000 in order to represent the leap second.
+    /// The offset in the current date is preserved.
+    ///
+    /// Returns `None` on invalid hour, minute, second and/or microsecond.
+    #[inline]
+    pub fn and_hms_micro_opt(
+        &self,
+        hour: u32,
+        min: u32,
+        sec: u32,
+        micro: u32,
+    ) -> Option<DateTime<Tz>> {
+        NaiveTime::from_hms_micro_opt(hour, min, sec, micro).and_then(|time| self.and_time(time))
+    }
+
+    /// Makes a new `DateTime` from the current date, hour, minute, second and nanosecond.
+    /// The nanosecond part can exceed 1,000,000,000 in order to represent the leap second.
+    /// The offset in the current date is preserved.
+    ///
+    /// Panics on invalid hour, minute, second and/or nanosecond.
+    #[deprecated(since = "0.4.23", note = "Use and_hms_nano_opt() instead")]
+    #[inline]
+    pub fn and_hms_nano(&self, hour: u32, min: u32, sec: u32, nano: u32) -> DateTime<Tz> {
+        self.and_hms_nano_opt(hour, min, sec, nano).expect("invalid time")
+    }
+
+    /// Makes a new `DateTime` from the current date, hour, minute, second and nanosecond.
+    /// The nanosecond part can exceed 1,000,000,000 in order to represent the leap second.
+    /// The offset in the current date is preserved.
+    ///
+    /// Returns `None` on invalid hour, minute, second and/or nanosecond.
+    #[inline]
+    pub fn and_hms_nano_opt(
+        &self,
+        hour: u32,
+        min: u32,
+        sec: u32,
+        nano: u32,
+    ) -> Option<DateTime<Tz>> {
+        NaiveTime::from_hms_nano_opt(hour, min, sec, nano).and_then(|time| self.and_time(time))
+    }
+
+    /// Makes a new `Date` for the next date.
+    ///
+    /// Panics when `self` is the last representable date.
+    #[deprecated(since = "0.4.23", note = "Use succ_opt() instead")]
+    #[inline]
+    pub fn succ(&self) -> Date<Tz> {
+        self.succ_opt().expect("out of bound")
+    }
+
+    /// Makes a new `Date` for the next date.
+    ///
+    /// Returns `None` when `self` is the last representable date.
+    #[inline]
+    pub fn succ_opt(&self) -> Option<Date<Tz>> {
+        self.date.succ_opt().map(|date| Date::from_utc(date, self.offset.clone()))
+    }
+
+    /// Makes a new `Date` for the prior date.
+    ///
+    /// Panics when `self` is the first representable date.
+    #[deprecated(since = "0.4.23", note = "Use pred_opt() instead")]
+    #[inline]
+    pub fn pred(&self) -> Date<Tz> {
+        self.pred_opt().expect("out of bound")
+    }
+
+    /// Makes a new `Date` for the prior date.
+    ///
+    /// Returns `None` when `self` is the first representable date.
+    #[inline]
+    pub fn pred_opt(&self) -> Option<Date<Tz>> {
+        self.date.pred_opt().map(|date| Date::from_utc(date, self.offset.clone()))
+    }
+
+    /// Retrieves an associated offset from UTC.
+    #[inline]
+    pub fn offset(&self) -> &Tz::Offset {
+        &self.offset
+    }
+
+    /// Retrieves an associated time zone.
+    #[inline]
+    pub fn timezone(&self) -> Tz {
+        TimeZone::from_offset(&self.offset)
+    }
+
+    /// Changes the associated time zone.
+    /// This does not change the actual `Date` (but will change the string representation).
+    #[inline]
+    pub fn with_timezone<Tz2: TimeZone>(&self, tz: &Tz2) -> Date<Tz2> {
+        tz.from_utc_date(&self.date)
+    }
+
+    /// Adds given `Duration` to the current date.
+    ///
+    /// Returns `None` when it will result in overflow.
+    #[inline]
+    pub fn checked_add_signed(self, rhs: OldDuration) -> Option<Date<Tz>> {
+        let date = self.date.checked_add_signed(rhs)?;
+        Some(Date { date, offset: self.offset })
+    }
+
+    /// Subtracts given `Duration` from the current date.
+    ///
+    /// Returns `None` when it will result in overflow.
+    #[inline]
+    pub fn checked_sub_signed(self, rhs: OldDuration) -> Option<Date<Tz>> {
+        let date = self.date.checked_sub_signed(rhs)?;
+        Some(Date { date, offset: self.offset })
+    }
+
+    /// Subtracts another `Date` from the current date.
+    /// Returns a `Duration` of integral numbers.
+    ///
+    /// This does not overflow or underflow at all,
+    /// as all possible output fits in the range of `Duration`.
+    #[inline]
+    pub fn signed_duration_since<Tz2: TimeZone>(self, rhs: Date<Tz2>) -> OldDuration {
+        self.date.signed_duration_since(rhs.date)
+    }
+
+    /// Returns a view to the naive UTC date.
+    #[inline]
+    pub fn naive_utc(&self) -> NaiveDate {
+        self.date
+    }
+
+    /// Returns a view to the naive local date.
+    ///
+    /// This is technically the same as [`naive_utc`](#method.naive_utc)
+    /// because the offset is restricted to never exceed one day,
+    /// but provided for the consistency.
+    #[inline]
+    pub fn naive_local(&self) -> NaiveDate {
+        self.date
+    }
+
+    /// Returns the number of whole years from the given `base` until `self`.
+    pub fn years_since(&self, base: Self) -> Option<u32> {
+        self.date.years_since(base.date)
+    }
+
+    /// The minimum possible `Date`.
+    pub const MIN_UTC: Date<Utc> = Date { date: NaiveDate::MIN, offset: Utc };
+    /// The maximum possible `Date`.
+    pub const MAX_UTC: Date<Utc> = Date { date: NaiveDate::MAX, offset: Utc };
+}
+
+/// Maps the local date to other date with given conversion function.
+fn map_local<Tz: TimeZone, F>(d: &Date<Tz>, mut f: F) -> Option<Date<Tz>>
+where
+    F: FnMut(NaiveDate) -> Option<NaiveDate>,
+{
+    f(d.naive_local()).and_then(|date| d.timezone().from_local_date(&date).single())
+}
+
+impl<Tz: TimeZone> Date<Tz>
+where
+    Tz::Offset: fmt::Display,
+{
+    /// Formats the date with the specified formatting items.
+    #[cfg(any(feature = "alloc", feature = "std", test))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "alloc", feature = "std"))))]
+    #[inline]
+    pub fn format_with_items<'a, I, B>(&self, items: I) -> DelayedFormat<I>
+    where
+        I: Iterator<Item = B> + Clone,
+        B: Borrow<Item<'a>>,
+    {
+        DelayedFormat::new_with_offset(Some(self.naive_local()), None, &self.offset, items)
+    }
+
+    /// Formats the date with the specified format string.
+    /// See the [`crate::format::strftime`] module
+    /// on the supported escape sequences.
+    #[cfg(any(feature = "alloc", feature = "std", test))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "alloc", feature = "std"))))]
+    #[inline]
+    pub fn format<'a>(&self, fmt: &'a str) -> DelayedFormat<StrftimeItems<'a>> {
+        self.format_with_items(StrftimeItems::new(fmt))
+    }
+
+    /// Formats the date with the specified formatting items and locale.
+    #[cfg(feature = "unstable-locales")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "unstable-locales")))]
+    #[inline]
+    pub fn format_localized_with_items<'a, I, B>(
+        &self,
+        items: I,
+        locale: Locale,
+    ) -> DelayedFormat<I>
+    where
+        I: Iterator<Item = B> + Clone,
+        B: Borrow<Item<'a>>,
+    {
+        DelayedFormat::new_with_offset_and_locale(
+            Some(self.naive_local()),
+            None,
+            &self.offset,
+            items,
+            locale,
+        )
+    }
+
+    /// Formats the date with the specified format string and locale.
+    /// See the [`crate::format::strftime`] module
+    /// on the supported escape sequences.
+    #[cfg(feature = "unstable-locales")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "unstable-locales")))]
+    #[inline]
+    pub fn format_localized<'a>(
+        &self,
+        fmt: &'a str,
+        locale: Locale,
+    ) -> DelayedFormat<StrftimeItems<'a>> {
+        self.format_localized_with_items(StrftimeItems::new_with_locale(fmt, locale), locale)
+    }
+}
+
+impl<Tz: TimeZone> Datelike for Date<Tz> {
+    #[inline]
+    fn year(&self) -> i32 {
+        self.naive_local().year()
+    }
+    #[inline]
+    fn month(&self) -> u32 {
+        self.naive_local().month()
+    }
+    #[inline]
+    fn month0(&self) -> u32 {
+        self.naive_local().month0()
+    }
+    #[inline]
+    fn day(&self) -> u32 {
+        self.naive_local().day()
+    }
+    #[inline]
+    fn day0(&self) -> u32 {
+        self.naive_local().day0()
+    }
+    #[inline]
+    fn ordinal(&self) -> u32 {
+        self.naive_local().ordinal()
+    }
+    #[inline]
+    fn ordinal0(&self) -> u32 {
+        self.naive_local().ordinal0()
+    }
+    #[inline]
+    fn weekday(&self) -> Weekday {
+        self.naive_local().weekday()
+    }
+    #[inline]
+    fn iso_week(&self) -> IsoWeek {
+        self.naive_local().iso_week()
+    }
+
+    #[inline]
+    fn with_year(&self, year: i32) -> Option<Date<Tz>> {
+        map_local(self, |date| date.with_year(year))
+    }
+
+    #[inline]
+    fn with_month(&self, month: u32) -> Option<Date<Tz>> {
+        map_local(self, |date| date.with_month(month))
+    }
+
+    #[inline]
+    fn with_month0(&self, month0: u32) -> Option<Date<Tz>> {
+        map_local(self, |date| date.with_month0(month0))
+    }
+
+    #[inline]
+    fn with_day(&self, day: u32) -> Option<Date<Tz>> {
+        map_local(self, |date| date.with_day(day))
+    }
+
+    #[inline]
+    fn with_day0(&self, day0: u32) -> Option<Date<Tz>> {
+        map_local(self, |date| date.with_day0(day0))
+    }
+
+    #[inline]
+    fn with_ordinal(&self, ordinal: u32) -> Option<Date<Tz>> {
+        map_local(self, |date| date.with_ordinal(ordinal))
+    }
+
+    #[inline]
+    fn with_ordinal0(&self, ordinal0: u32) -> Option<Date<Tz>> {
+        map_local(self, |date| date.with_ordinal0(ordinal0))
+    }
+}
+
+// we need them as automatic impls cannot handle associated types
+impl<Tz: TimeZone> Copy for Date<Tz> where <Tz as TimeZone>::Offset: Copy {}
+unsafe impl<Tz: TimeZone> Send for Date<Tz> where <Tz as TimeZone>::Offset: Send {}
+
+impl<Tz: TimeZone, Tz2: TimeZone> PartialEq<Date<Tz2>> for Date<Tz> {
+    fn eq(&self, other: &Date<Tz2>) -> bool {
+        self.date == other.date
+    }
+}
+
+impl<Tz: TimeZone> Eq for Date<Tz> {}
+
+impl<Tz: TimeZone> PartialOrd for Date<Tz> {
+    fn partial_cmp(&self, other: &Date<Tz>) -> Option<Ordering> {
+        self.date.partial_cmp(&other.date)
+    }
+}
+
+impl<Tz: TimeZone> Ord for Date<Tz> {
+    fn cmp(&self, other: &Date<Tz>) -> Ordering {
+        self.date.cmp(&other.date)
+    }
+}
+
+impl<Tz: TimeZone> hash::Hash for Date<Tz> {
+    fn hash<H: hash::Hasher>(&self, state: &mut H) {
+        self.date.hash(state)
+    }
+}
+
+impl<Tz: TimeZone> Add<OldDuration> for Date<Tz> {
+    type Output = Date<Tz>;
+
+    #[inline]
+    fn add(self, rhs: OldDuration) -> Date<Tz> {
+        self.checked_add_signed(rhs).expect("`Date + Duration` overflowed")
+    }
+}
+
+impl<Tz: TimeZone> AddAssign<OldDuration> for Date<Tz> {
+    #[inline]
+    fn add_assign(&mut self, rhs: OldDuration) {
+        self.date = self.date.checked_add_signed(rhs).expect("`Date + Duration` overflowed");
+    }
+}
+
+impl<Tz: TimeZone> Sub<OldDuration> for Date<Tz> {
+    type Output = Date<Tz>;
+
+    #[inline]
+    fn sub(self, rhs: OldDuration) -> Date<Tz> {
+        self.checked_sub_signed(rhs).expect("`Date - Duration` overflowed")
+    }
+}
+
+impl<Tz: TimeZone> SubAssign<OldDuration> for Date<Tz> {
+    #[inline]
+    fn sub_assign(&mut self, rhs: OldDuration) {
+        self.date = self.date.checked_sub_signed(rhs).expect("`Date - Duration` overflowed");
+    }
+}
+
+impl<Tz: TimeZone> Sub<Date<Tz>> for Date<Tz> {
+    type Output = OldDuration;
+
+    #[inline]
+    fn sub(self, rhs: Date<Tz>) -> OldDuration {
+        self.signed_duration_since(rhs)
+    }
+}
+
+impl<Tz: TimeZone> fmt::Debug for Date<Tz> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        self.naive_local().fmt(f)?;
+        self.offset.fmt(f)
+    }
+}
+
+impl<Tz: TimeZone> fmt::Display for Date<Tz>
+where
+    Tz::Offset: fmt::Display,
+{
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        self.naive_local().fmt(f)?;
+        self.offset.fmt(f)
+    }
+}
+
+// Note that implementation of Arbitrary cannot be automatically derived for Date<Tz>, due to
+// the nontrivial bound <Tz as TimeZone>::Offset: Arbitrary.
+#[cfg(feature = "arbitrary")]
+impl<'a, Tz> arbitrary::Arbitrary<'a> for Date<Tz>
+where
+    Tz: TimeZone,
+    <Tz as TimeZone>::Offset: arbitrary::Arbitrary<'a>,
+{
+    fn arbitrary(u: &mut arbitrary::Unstructured<'a>) -> arbitrary::Result<Date<Tz>> {
+        let date = NaiveDate::arbitrary(u)?;
+        let offset = <Tz as TimeZone>::Offset::arbitrary(u)?;
+        Ok(Date::from_utc(date, offset))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Date;
+
+    use crate::oldtime::Duration;
+    use crate::{FixedOffset, NaiveDate, Utc};
+
+    #[cfg(feature = "clock")]
+    use crate::offset::{Local, TimeZone};
+
+    #[test]
+    #[cfg(feature = "clock")]
+    fn test_years_elapsed() {
+        const WEEKS_PER_YEAR: f32 = 52.1775;
+
+        // This is always at least one year because 1 year = 52.1775 weeks.
+        let one_year_ago = Utc::today() - Duration::weeks((WEEKS_PER_YEAR * 1.5).ceil() as i64);
+        // A bit more than 2 years.
+        let two_year_ago = Utc::today() - Duration::weeks((WEEKS_PER_YEAR * 2.5).ceil() as i64);
+
+        assert_eq!(Utc::today().years_since(one_year_ago), Some(1));
+        assert_eq!(Utc::today().years_since(two_year_ago), Some(2));
+
+        // If the given DateTime is later than now, the function will always return 0.
+        let future = Utc::today() + Duration::weeks(12);
+        assert_eq!(Utc::today().years_since(future), None);
+    }
+
+    #[test]
+    fn test_date_add_assign() {
+        let naivedate = NaiveDate::from_ymd_opt(2000, 1, 1).unwrap();
+        let date = Date::<Utc>::from_utc(naivedate, Utc);
+        let mut date_add = date;
+
+        date_add += Duration::days(5);
+        assert_eq!(date_add, date + Duration::days(5));
+
+        let timezone = FixedOffset::east_opt(60 * 60).unwrap();
+        let date = date.with_timezone(&timezone);
+        let date_add = date_add.with_timezone(&timezone);
+
+        assert_eq!(date_add, date + Duration::days(5));
+
+        let timezone = FixedOffset::west_opt(2 * 60 * 60).unwrap();
+        let date = date.with_timezone(&timezone);
+        let date_add = date_add.with_timezone(&timezone);
+
+        assert_eq!(date_add, date + Duration::days(5));
+    }
+
+    #[test]
+    #[cfg(feature = "clock")]
+    fn test_date_add_assign_local() {
+        let naivedate = NaiveDate::from_ymd_opt(2000, 1, 1).unwrap();
+
+        let date = Local.from_utc_date(&naivedate);
+        let mut date_add = date;
+
+        date_add += Duration::days(5);
+        assert_eq!(date_add, date + Duration::days(5));
+    }
+
+    #[test]
+    fn test_date_sub_assign() {
+        let naivedate = NaiveDate::from_ymd_opt(2000, 1, 1).unwrap();
+        let date = Date::<Utc>::from_utc(naivedate, Utc);
+        let mut date_sub = date;
+
+        date_sub -= Duration::days(5);
+        assert_eq!(date_sub, date - Duration::days(5));
+
+        let timezone = FixedOffset::east_opt(60 * 60).unwrap();
+        let date = date.with_timezone(&timezone);
+        let date_sub = date_sub.with_timezone(&timezone);
+
+        assert_eq!(date_sub, date - Duration::days(5));
+
+        let timezone = FixedOffset::west_opt(2 * 60 * 60).unwrap();
+        let date = date.with_timezone(&timezone);
+        let date_sub = date_sub.with_timezone(&timezone);
+
+        assert_eq!(date_sub, date - Duration::days(5));
+    }
+
+    #[test]
+    #[cfg(feature = "clock")]
+    fn test_date_sub_assign_local() {
+        let naivedate = NaiveDate::from_ymd_opt(2000, 1, 1).unwrap();
+
+        let date = Local.from_utc_date(&naivedate);
+        let mut date_sub = date;
+
+        date_sub -= Duration::days(5);
+        assert_eq!(date_sub, date - Duration::days(5));
+    }
+}

javascript-engine/external/chrono/src/datetime/rustc_serialize.rs

@@ -0,0 +1,123 @@
+#![cfg_attr(docsrs, doc(cfg(feature = "rustc-serialize")))]
+
+use super::DateTime;
+#[cfg(feature = "clock")]
+use crate::offset::Local;
+use crate::offset::{FixedOffset, LocalResult, TimeZone, Utc};
+use core::fmt;
+use core::ops::Deref;
+use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
+
+impl<Tz: TimeZone> Encodable for DateTime<Tz> {
+    fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
+        format!("{:?}", self).encode(s)
+    }
+}
+
+// lik? function to convert a LocalResult into a serde-ish Result
+fn from<T, D>(me: LocalResult<T>, d: &mut D) -> Result<T, D::Error>
+where
+    D: Decoder,
+    T: fmt::Display,
+{
+    match me {
+        LocalResult::None => Err(d.error("value is not a legal timestamp")),
+        LocalResult::Ambiguous(..) => Err(d.error("value is an ambiguous timestamp")),
+        LocalResult::Single(val) => Ok(val),
+    }
+}
+
+impl Decodable for DateTime<FixedOffset> {
+    fn decode<D: Decoder>(d: &mut D) -> Result<DateTime<FixedOffset>, D::Error> {
+        d.read_str()?.parse::<DateTime<FixedOffset>>().map_err(|_| d.error("invalid date and time"))
+    }
+}
+
+#[allow(deprecated)]
+impl Decodable for TsSeconds<FixedOffset> {
+    #[allow(deprecated)]
+    fn decode<D: Decoder>(d: &mut D) -> Result<TsSeconds<FixedOffset>, D::Error> {
+        from(FixedOffset::east_opt(0).unwrap().timestamp_opt(d.read_i64()?, 0), d).map(TsSeconds)
+    }
+}
+
+impl Decodable for DateTime<Utc> {
+    fn decode<D: Decoder>(d: &mut D) -> Result<DateTime<Utc>, D::Error> {
+        d.read_str()?
+            .parse::<DateTime<FixedOffset>>()
+            .map(|dt| dt.with_timezone(&Utc))
+            .map_err(|_| d.error("invalid date and time"))
+    }
+}
+
+/// A [`DateTime`] that can be deserialized from a timestamp
+///
+/// A timestamp here is seconds since the epoch
+#[derive(Debug)]
+pub struct TsSeconds<Tz: TimeZone>(DateTime<Tz>);
+
+#[allow(deprecated)]
+impl<Tz: TimeZone> From<TsSeconds<Tz>> for DateTime<Tz> {
+    /// Pull the inner `DateTime<Tz>` out
+    #[allow(deprecated)]
+    fn from(obj: TsSeconds<Tz>) -> DateTime<Tz> {
+        obj.0
+    }
+}
+
+#[allow(deprecated)]
+impl<Tz: TimeZone> Deref for TsSeconds<Tz> {
+    type Target = DateTime<Tz>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[allow(deprecated)]
+impl Decodable for TsSeconds<Utc> {
+    fn decode<D: Decoder>(d: &mut D) -> Result<TsSeconds<Utc>, D::Error> {
+        from(Utc.timestamp_opt(d.read_i64()?, 0), d).map(TsSeconds)
+    }
+}
+
+#[cfg(feature = "clock")]
+#[cfg_attr(docsrs, doc(cfg(feature = "clock")))]
+impl Decodable for DateTime<Local> {
+    fn decode<D: Decoder>(d: &mut D) -> Result<DateTime<Local>, D::Error> {
+        match d.read_str()?.parse::<DateTime<FixedOffset>>() {
+            Ok(dt) => Ok(dt.with_timezone(&Local)),
+            Err(_) => Err(d.error("invalid date and time")),
+        }
+    }
+}
+
+#[cfg(feature = "clock")]
+#[cfg_attr(docsrs, doc(cfg(feature = "clock")))]
+#[allow(deprecated)]
+impl Decodable for TsSeconds<Local> {
+    #[allow(deprecated)]
+    fn decode<D: Decoder>(d: &mut D) -> Result<TsSeconds<Local>, D::Error> {
+        from(Utc.timestamp_opt(d.read_i64()?, 0), d).map(|dt| TsSeconds(dt.with_timezone(&Local)))
+    }
+}
+
+#[cfg(test)]
+use rustc_serialize::json;
+
+#[test]
+fn test_encodable() {
+    super::test_encodable_json(json::encode, json::encode);
+}
+
+#[cfg(feature = "clock")]
+#[test]
+fn test_decodable() {
+    super::test_decodable_json(json::decode, json::decode, json::decode);
+}
+
+#[cfg(feature = "clock")]
+#[test]
+fn test_decodable_timestamps() {
+    super::test_decodable_json_timestamps(json::decode, json::decode, json::decode);
+}

javascript-engine/external/chrono/src/datetime/tests.rs

@@ -0,0 +1,952 @@
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use super::DateTime;
+use crate::naive::{NaiveDate, NaiveTime};
+#[cfg(feature = "clock")]
+use crate::offset::Local;
+use crate::offset::{FixedOffset, TimeZone, Utc};
+use crate::oldtime::Duration;
+#[cfg(feature = "clock")]
+use crate::Datelike;
+use crate::{Days, LocalResult, Months, NaiveDateTime};
+
+#[derive(Clone)]
+struct DstTester;
+
+impl DstTester {
+    fn winter_offset() -> FixedOffset {
+        FixedOffset::east_opt(8 * 60 * 60).unwrap()
+    }
+    fn summer_offset() -> FixedOffset {
+        FixedOffset::east_opt(9 * 60 * 60).unwrap()
+    }
+
+    const TO_WINTER_MONTH_DAY: (u32, u32) = (4, 15);
+    const TO_SUMMER_MONTH_DAY: (u32, u32) = (9, 15);
+
+    fn transition_start_local() -> NaiveTime {
+        NaiveTime::from_hms_opt(2, 0, 0).unwrap()
+    }
+}
+
+impl TimeZone for DstTester {
+    type Offset = FixedOffset;
+
+    fn from_offset(_: &Self::Offset) -> Self {
+        DstTester
+    }
+
+    fn offset_from_local_date(&self, _: &NaiveDate) -> crate::LocalResult<Self::Offset> {
+        unimplemented!()
+    }
+
+    fn offset_from_local_datetime(
+        &self,
+        local: &NaiveDateTime,
+    ) -> crate::LocalResult<Self::Offset> {
+        let local_to_winter_transition_start = NaiveDate::from_ymd_opt(
+            local.year(),
+            DstTester::TO_WINTER_MONTH_DAY.0,
+            DstTester::TO_WINTER_MONTH_DAY.1,
+        )
+        .unwrap()
+        .and_time(DstTester::transition_start_local());
+
+        let local_to_winter_transition_end = NaiveDate::from_ymd_opt(
+            local.year(),
+            DstTester::TO_WINTER_MONTH_DAY.0,
+            DstTester::TO_WINTER_MONTH_DAY.1,
+        )
+        .unwrap()
+        .and_time(DstTester::transition_start_local() - Duration::hours(1));
+
+        let local_to_summer_transition_start = NaiveDate::from_ymd_opt(
+            local.year(),
+            DstTester::TO_SUMMER_MONTH_DAY.0,
+            DstTester::TO_SUMMER_MONTH_DAY.1,
+        )
+        .unwrap()
+        .and_time(DstTester::transition_start_local());
+
+        let local_to_summer_transition_end = NaiveDate::from_ymd_opt(
+            local.year(),
+            DstTester::TO_SUMMER_MONTH_DAY.0,
+            DstTester::TO_SUMMER_MONTH_DAY.1,
+        )
+        .unwrap()
+        .and_time(DstTester::transition_start_local() + Duration::hours(1));
+
+        if *local < local_to_winter_transition_end || *local >= local_to_summer_transition_end {
+            LocalResult::Single(DstTester::summer_offset())
+        } else if *local >= local_to_winter_transition_start
+            && *local < local_to_summer_transition_start
+        {
+            LocalResult::Single(DstTester::winter_offset())
+        } else if *local >= local_to_winter_transition_end
+            && *local < local_to_winter_transition_start
+        {
+            LocalResult::Ambiguous(DstTester::winter_offset(), DstTester::summer_offset())
+        } else if *local >= local_to_summer_transition_start
+            && *local < local_to_summer_transition_end
+        {
+            LocalResult::None
+        } else {
+            panic!("Unexpected local time {}", local)
+        }
+    }
+
+    fn offset_from_utc_date(&self, _: &NaiveDate) -> Self::Offset {
+        unimplemented!()
+    }
+
+    fn offset_from_utc_datetime(&self, utc: &NaiveDateTime) -> Self::Offset {
+        let utc_to_winter_transition = NaiveDate::from_ymd_opt(
+            utc.year(),
+            DstTester::TO_WINTER_MONTH_DAY.0,
+            DstTester::TO_WINTER_MONTH_DAY.1,
+        )
+        .unwrap()
+        .and_time(DstTester::transition_start_local())
+            - DstTester::summer_offset();
+
+        let utc_to_summer_transition = NaiveDate::from_ymd_opt(
+            utc.year(),
+            DstTester::TO_SUMMER_MONTH_DAY.0,
+            DstTester::TO_SUMMER_MONTH_DAY.1,
+        )
+        .unwrap()
+        .and_time(DstTester::transition_start_local())
+            - DstTester::winter_offset();
+
+        if *utc < utc_to_winter_transition || *utc >= utc_to_summer_transition {
+            DstTester::summer_offset()
+        } else if *utc >= utc_to_winter_transition && *utc < utc_to_summer_transition {
+            DstTester::winter_offset()
+        } else {
+            panic!("Unexpected utc time {}", utc)
+        }
+    }
+}
+
+#[test]
+fn test_datetime_add_days() {
+    let est = FixedOffset::west_opt(5 * 60 * 60).unwrap();
+    let kst = FixedOffset::east_opt(9 * 60 * 60).unwrap();
+
+    assert_eq!(
+        format!("{}", est.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap() + Days::new(5)),
+        "2014-05-11 07:08:09 -05:00"
+    );
+    assert_eq!(
+        format!("{}", kst.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap() + Days::new(5)),
+        "2014-05-11 07:08:09 +09:00"
+    );
+
+    assert_eq!(
+        format!("{}", est.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap() + Days::new(35)),
+        "2014-06-10 07:08:09 -05:00"
+    );
+    assert_eq!(
+        format!("{}", kst.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap() + Days::new(35)),
+        "2014-06-10 07:08:09 +09:00"
+    );
+
+    assert_eq!(
+        format!("{}", DstTester.with_ymd_and_hms(2014, 4, 6, 7, 8, 9).unwrap() + Days::new(5)),
+        "2014-04-11 07:08:09 +09:00"
+    );
+    assert_eq!(
+        format!("{}", DstTester.with_ymd_and_hms(2014, 4, 6, 7, 8, 9).unwrap() + Days::new(10)),
+        "2014-04-16 07:08:09 +08:00"
+    );
+
+    assert_eq!(
+        format!("{}", DstTester.with_ymd_and_hms(2014, 9, 6, 7, 8, 9).unwrap() + Days::new(5)),
+        "2014-09-11 07:08:09 +08:00"
+    );
+    assert_eq!(
+        format!("{}", DstTester.with_ymd_and_hms(2014, 9, 6, 7, 8, 9).unwrap() + Days::new(10)),
+        "2014-09-16 07:08:09 +09:00"
+    );
+}
+
+#[test]
+fn test_datetime_sub_days() {
+    let est = FixedOffset::west_opt(5 * 60 * 60).unwrap();
+    let kst = FixedOffset::east_opt(9 * 60 * 60).unwrap();
+
+    assert_eq!(
+        format!("{}", est.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap() - Days::new(5)),
+        "2014-05-01 07:08:09 -05:00"
+    );
+    assert_eq!(
+        format!("{}", kst.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap() - Days::new(5)),
+        "2014-05-01 07:08:09 +09:00"
+    );
+
+    assert_eq!(
+        format!("{}", est.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap() - Days::new(35)),
+        "2014-04-01 07:08:09 -05:00"
+    );
+    assert_eq!(
+        format!("{}", kst.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap() - Days::new(35)),
+        "2014-04-01 07:08:09 +09:00"
+    );
+}
+
+#[test]
+fn test_datetime_add_months() {
+    let est = FixedOffset::west_opt(5 * 60 * 60).unwrap();
+    let kst = FixedOffset::east_opt(9 * 60 * 60).unwrap();
+
+    assert_eq!(
+        format!("{}", est.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap() + Months::new(1)),
+        "2014-06-06 07:08:09 -05:00"
+    );
+    assert_eq!(
+        format!("{}", kst.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap() + Months::new(1)),
+        "2014-06-06 07:08:09 +09:00"
+    );
+
+    assert_eq!(
+        format!("{}", est.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap() + Months::new(5)),
+        "2014-10-06 07:08:09 -05:00"
+    );
+    assert_eq!(
+        format!("{}", kst.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap() + Months::new(5)),
+        "2014-10-06 07:08:09 +09:00"
+    );
+}
+
+#[test]
+fn test_datetime_sub_months() {
+    let est = FixedOffset::west_opt(5 * 60 * 60).unwrap();
+    let kst = FixedOffset::east_opt(9 * 60 * 60).unwrap();
+
+    assert_eq!(
+        format!("{}", est.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap() - Months::new(1)),
+        "2014-04-06 07:08:09 -05:00"
+    );
+    assert_eq!(
+        format!("{}", kst.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap() - Months::new(1)),
+        "2014-04-06 07:08:09 +09:00"
+    );
+
+    assert_eq!(
+        format!("{}", est.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap() - Months::new(5)),
+        "2013-12-06 07:08:09 -05:00"
+    );
+    assert_eq!(
+        format!("{}", kst.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap() - Months::new(5)),
+        "2013-12-06 07:08:09 +09:00"
+    );
+}
+
+#[test]
+fn test_datetime_offset() {
+    let est = FixedOffset::west_opt(5 * 60 * 60).unwrap();
+    let edt = FixedOffset::west_opt(4 * 60 * 60).unwrap();
+    let kst = FixedOffset::east_opt(9 * 60 * 60).unwrap();
+
+    assert_eq!(
+        format!("{}", Utc.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap()),
+        "2014-05-06 07:08:09 UTC"
+    );
+    assert_eq!(
+        format!("{}", edt.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap()),
+        "2014-05-06 07:08:09 -04:00"
+    );
+    assert_eq!(
+        format!("{}", kst.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap()),
+        "2014-05-06 07:08:09 +09:00"
+    );
+    assert_eq!(
+        format!("{:?}", Utc.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap()),
+        "2014-05-06T07:08:09Z"
+    );
+    assert_eq!(
+        format!("{:?}", edt.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap()),
+        "2014-05-06T07:08:09-04:00"
+    );
+    assert_eq!(
+        format!("{:?}", kst.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap()),
+        "2014-05-06T07:08:09+09:00"
+    );
+
+    // edge cases
+    assert_eq!(
+        format!("{:?}", Utc.with_ymd_and_hms(2014, 5, 6, 0, 0, 0).unwrap()),
+        "2014-05-06T00:00:00Z"
+    );
+    assert_eq!(
+        format!("{:?}", edt.with_ymd_and_hms(2014, 5, 6, 0, 0, 0).unwrap()),
+        "2014-05-06T00:00:00-04:00"
+    );
+    assert_eq!(
+        format!("{:?}", kst.with_ymd_and_hms(2014, 5, 6, 0, 0, 0).unwrap()),
+        "2014-05-06T00:00:00+09:00"
+    );
+    assert_eq!(
+        format!("{:?}", Utc.with_ymd_and_hms(2014, 5, 6, 23, 59, 59).unwrap()),
+        "2014-05-06T23:59:59Z"
+    );
+    assert_eq!(
+        format!("{:?}", edt.with_ymd_and_hms(2014, 5, 6, 23, 59, 59).unwrap()),
+        "2014-05-06T23:59:59-04:00"
+    );
+    assert_eq!(
+        format!("{:?}", kst.with_ymd_and_hms(2014, 5, 6, 23, 59, 59).unwrap()),
+        "2014-05-06T23:59:59+09:00"
+    );
+
+    let dt = Utc.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap();
+    assert_eq!(dt, edt.with_ymd_and_hms(2014, 5, 6, 3, 8, 9).unwrap());
+    assert_eq!(
+        dt + Duration::seconds(3600 + 60 + 1),
+        Utc.with_ymd_and_hms(2014, 5, 6, 8, 9, 10).unwrap()
+    );
+    assert_eq!(
+        dt.signed_duration_since(edt.with_ymd_and_hms(2014, 5, 6, 10, 11, 12).unwrap()),
+        Duration::seconds(-7 * 3600 - 3 * 60 - 3)
+    );
+
+    assert_eq!(*Utc.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap().offset(), Utc);
+    assert_eq!(*edt.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap().offset(), edt);
+    assert!(*edt.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap().offset() != est);
+}
+
+#[test]
+fn test_datetime_date_and_time() {
+    let tz = FixedOffset::east_opt(5 * 60 * 60).unwrap();
+    let d = tz.with_ymd_and_hms(2014, 5, 6, 7, 8, 9).unwrap();
+    assert_eq!(d.time(), NaiveTime::from_hms_opt(7, 8, 9).unwrap());
+    assert_eq!(d.date_naive(), NaiveDate::from_ymd_opt(2014, 5, 6).unwrap());
+
+    let tz = FixedOffset::east_opt(4 * 60 * 60).unwrap();
+    let d = tz.with_ymd_and_hms(2016, 5, 4, 3, 2, 1).unwrap();
+    assert_eq!(d.time(), NaiveTime::from_hms_opt(3, 2, 1).unwrap());
+    assert_eq!(d.date_naive(), NaiveDate::from_ymd_opt(2016, 5, 4).unwrap());
+
+    let tz = FixedOffset::west_opt(13 * 60 * 60).unwrap();
+    let d = tz.with_ymd_and_hms(2017, 8, 9, 12, 34, 56).unwrap();
+    assert_eq!(d.time(), NaiveTime::from_hms_opt(12, 34, 56).unwrap());
+    assert_eq!(d.date_naive(), NaiveDate::from_ymd_opt(2017, 8, 9).unwrap());
+
+    let utc_d = Utc.with_ymd_and_hms(2017, 8, 9, 12, 34, 56).unwrap();
+    assert!(utc_d < d);
+}
+
+#[test]
+#[cfg(feature = "clock")]
+fn test_datetime_with_timezone() {
+    let local_now = Local::now();
+    let utc_now = local_now.with_timezone(&Utc);
+    let local_now2 = utc_now.with_timezone(&Local);
+    assert_eq!(local_now, local_now2);
+}
+
+#[test]
+fn test_datetime_rfc2822_and_rfc3339() {
+    let edt = FixedOffset::east_opt(5 * 60 * 60).unwrap();
+    assert_eq!(
+        Utc.with_ymd_and_hms(2015, 2, 18, 23, 16, 9).unwrap().to_rfc2822(),
+        "Wed, 18 Feb 2015 23:16:09 +0000"
+    );
+    assert_eq!(
+        Utc.with_ymd_and_hms(2015, 2, 18, 23, 16, 9).unwrap().to_rfc3339(),
+        "2015-02-18T23:16:09+00:00"
+    );
+    assert_eq!(
+        edt.from_local_datetime(
+            &NaiveDate::from_ymd_opt(2015, 2, 18)
+                .unwrap()
+                .and_hms_milli_opt(23, 16, 9, 150)
+                .unwrap()
+        )
+        .unwrap()
+        .to_rfc2822(),
+        "Wed, 18 Feb 2015 23:16:09 +0500"
+    );
+    assert_eq!(
+        edt.from_local_datetime(
+            &NaiveDate::from_ymd_opt(2015, 2, 18)
+                .unwrap()
+                .and_hms_milli_opt(23, 16, 9, 150)
+                .unwrap()
+        )
+        .unwrap()
+        .to_rfc3339(),
+        "2015-02-18T23:16:09.150+05:00"
+    );
+    assert_eq!(
+        edt.from_local_datetime(
+            &NaiveDate::from_ymd_opt(2015, 2, 18)
+                .unwrap()
+                .and_hms_micro_opt(23, 59, 59, 1_234_567)
+                .unwrap()
+        )
+        .unwrap()
+        .to_rfc2822(),
+        "Wed, 18 Feb 2015 23:59:60 +0500"
+    );
+    assert_eq!(
+        edt.from_local_datetime(
+            &NaiveDate::from_ymd_opt(2015, 2, 18)
+                .unwrap()
+                .and_hms_micro_opt(23, 59, 59, 1_234_567)
+                .unwrap()
+        )
+        .unwrap()
+        .to_rfc3339(),
+        "2015-02-18T23:59:60.234567+05:00"
+    );
+
+    assert_eq!(
+        DateTime::parse_from_rfc2822("Wed, 18 Feb 2015 23:16:09 +0000"),
+        Ok(FixedOffset::east_opt(0).unwrap().with_ymd_and_hms(2015, 2, 18, 23, 16, 9).unwrap())
+    );
+    assert_eq!(
+        DateTime::parse_from_rfc2822("Wed, 18 Feb 2015 23:16:09 -0000"),
+        Ok(FixedOffset::east_opt(0).unwrap().with_ymd_and_hms(2015, 2, 18, 23, 16, 9).unwrap())
+    );
+    assert_eq!(
+        DateTime::parse_from_rfc3339("2015-02-18T23:16:09Z"),
+        Ok(FixedOffset::east_opt(0).unwrap().with_ymd_and_hms(2015, 2, 18, 23, 16, 9).unwrap())
+    );
+    assert_eq!(
+        DateTime::parse_from_rfc2822("Wed, 18 Feb 2015 23:59:60 +0500"),
+        Ok(edt
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2015, 2, 18)
+                    .unwrap()
+                    .and_hms_milli_opt(23, 59, 59, 1_000)
+                    .unwrap()
+            )
+            .unwrap())
+    );
+    assert!(DateTime::parse_from_rfc2822("31 DEC 262143 23:59 -2359").is_err());
+    assert_eq!(
+        DateTime::parse_from_rfc3339("2015-02-18T23:59:60.234567+05:00"),
+        Ok(edt
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2015, 2, 18)
+                    .unwrap()
+                    .and_hms_micro_opt(23, 59, 59, 1_234_567)
+                    .unwrap()
+            )
+            .unwrap())
+    );
+}
+
+#[test]
+fn test_rfc3339_opts() {
+    use crate::SecondsFormat::*;
+    let pst = FixedOffset::east_opt(8 * 60 * 60).unwrap();
+    let dt = pst
+        .from_local_datetime(
+            &NaiveDate::from_ymd_opt(2018, 1, 11)
+                .unwrap()
+                .and_hms_nano_opt(10, 5, 13, 84_660_000)
+                .unwrap(),
+        )
+        .unwrap();
+    assert_eq!(dt.to_rfc3339_opts(Secs, false), "2018-01-11T10:05:13+08:00");
+    assert_eq!(dt.to_rfc3339_opts(Secs, true), "2018-01-11T10:05:13+08:00");
+    assert_eq!(dt.to_rfc3339_opts(Millis, false), "2018-01-11T10:05:13.084+08:00");
+    assert_eq!(dt.to_rfc3339_opts(Micros, false), "2018-01-11T10:05:13.084660+08:00");
+    assert_eq!(dt.to_rfc3339_opts(Nanos, false), "2018-01-11T10:05:13.084660000+08:00");
+    assert_eq!(dt.to_rfc3339_opts(AutoSi, false), "2018-01-11T10:05:13.084660+08:00");
+
+    let ut = DateTime::<Utc>::from_utc(dt.naive_utc(), Utc);
+    assert_eq!(ut.to_rfc3339_opts(Secs, false), "2018-01-11T02:05:13+00:00");
+    assert_eq!(ut.to_rfc3339_opts(Secs, true), "2018-01-11T02:05:13Z");
+    assert_eq!(ut.to_rfc3339_opts(Millis, false), "2018-01-11T02:05:13.084+00:00");
+    assert_eq!(ut.to_rfc3339_opts(Millis, true), "2018-01-11T02:05:13.084Z");
+    assert_eq!(ut.to_rfc3339_opts(Micros, true), "2018-01-11T02:05:13.084660Z");
+    assert_eq!(ut.to_rfc3339_opts(Nanos, true), "2018-01-11T02:05:13.084660000Z");
+    assert_eq!(ut.to_rfc3339_opts(AutoSi, true), "2018-01-11T02:05:13.084660Z");
+}
+
+#[test]
+#[should_panic]
+fn test_rfc3339_opts_nonexhaustive() {
+    use crate::SecondsFormat;
+    let dt = Utc.with_ymd_and_hms(1999, 10, 9, 1, 2, 3).unwrap();
+    dt.to_rfc3339_opts(SecondsFormat::__NonExhaustive, true);
+}
+
+#[test]
+fn test_datetime_from_str() {
+    assert_eq!(
+        "2015-02-18T23:16:9.15Z".parse::<DateTime<FixedOffset>>(),
+        Ok(FixedOffset::east_opt(0)
+            .unwrap()
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2015, 2, 18)
+                    .unwrap()
+                    .and_hms_milli_opt(23, 16, 9, 150)
+                    .unwrap()
+            )
+            .unwrap())
+    );
+    assert_eq!(
+        "2015-02-18T23:16:9.15Z".parse::<DateTime<Utc>>(),
+        Ok(Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2015, 2, 18)
+                    .unwrap()
+                    .and_hms_milli_opt(23, 16, 9, 150)
+                    .unwrap()
+            )
+            .unwrap())
+    );
+    assert_eq!(
+        "2015-02-18T23:16:9.15 UTC".parse::<DateTime<Utc>>(),
+        Ok(Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2015, 2, 18)
+                    .unwrap()
+                    .and_hms_milli_opt(23, 16, 9, 150)
+                    .unwrap()
+            )
+            .unwrap())
+    );
+    assert_eq!(
+        "2015-02-18T23:16:9.15UTC".parse::<DateTime<Utc>>(),
+        Ok(Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2015, 2, 18)
+                    .unwrap()
+                    .and_hms_milli_opt(23, 16, 9, 150)
+                    .unwrap()
+            )
+            .unwrap())
+    );
+
+    assert_eq!(
+        "2015-2-18T23:16:9.15Z".parse::<DateTime<FixedOffset>>(),
+        Ok(FixedOffset::east_opt(0)
+            .unwrap()
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2015, 2, 18)
+                    .unwrap()
+                    .and_hms_milli_opt(23, 16, 9, 150)
+                    .unwrap()
+            )
+            .unwrap())
+    );
+    assert_eq!(
+        "2015-2-18T13:16:9.15-10:00".parse::<DateTime<FixedOffset>>(),
+        Ok(FixedOffset::west_opt(10 * 3600)
+            .unwrap()
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2015, 2, 18)
+                    .unwrap()
+                    .and_hms_milli_opt(13, 16, 9, 150)
+                    .unwrap()
+            )
+            .unwrap())
+    );
+    assert!("2015-2-18T23:16:9.15".parse::<DateTime<FixedOffset>>().is_err());
+
+    assert_eq!(
+        "2015-2-18T23:16:9.15Z".parse::<DateTime<Utc>>(),
+        Ok(Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2015, 2, 18)
+                    .unwrap()
+                    .and_hms_milli_opt(23, 16, 9, 150)
+                    .unwrap()
+            )
+            .unwrap())
+    );
+    assert_eq!(
+        "2015-2-18T13:16:9.15-10:00".parse::<DateTime<Utc>>(),
+        Ok(Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2015, 2, 18)
+                    .unwrap()
+                    .and_hms_milli_opt(23, 16, 9, 150)
+                    .unwrap()
+            )
+            .unwrap())
+    );
+    assert!("2015-2-18T23:16:9.15".parse::<DateTime<Utc>>().is_err());
+
+    // no test for `DateTime<Local>`, we cannot verify that much.
+}
+
+#[test]
+fn test_datetime_parse_from_str() {
+    let ymdhms = |y, m, d, h, n, s, off| {
+        FixedOffset::east_opt(off).unwrap().with_ymd_and_hms(y, m, d, h, n, s).unwrap()
+    };
+    assert_eq!(
+        DateTime::parse_from_str("2014-5-7T12:34:56+09:30", "%Y-%m-%dT%H:%M:%S%z"),
+        Ok(ymdhms(2014, 5, 7, 12, 34, 56, 570 * 60))
+    ); // ignore offset
+    assert!(DateTime::parse_from_str("20140507000000", "%Y%m%d%H%M%S").is_err()); // no offset
+    assert!(DateTime::parse_from_str("Fri, 09 Aug 2013 23:54:35 GMT", "%a, %d %b %Y %H:%M:%S GMT")
+        .is_err());
+    assert_eq!(
+        Utc.datetime_from_str("Fri, 09 Aug 2013 23:54:35 GMT", "%a, %d %b %Y %H:%M:%S GMT"),
+        Ok(Utc.with_ymd_and_hms(2013, 8, 9, 23, 54, 35).unwrap())
+    );
+}
+
+#[test]
+fn test_to_string_round_trip() {
+    let dt = Utc.with_ymd_and_hms(2000, 1, 1, 0, 0, 0).unwrap();
+    let _dt: DateTime<Utc> = dt.to_string().parse().unwrap();
+
+    let ndt_fixed = dt.with_timezone(&FixedOffset::east_opt(3600).unwrap());
+    let _dt: DateTime<FixedOffset> = ndt_fixed.to_string().parse().unwrap();
+
+    let ndt_fixed = dt.with_timezone(&FixedOffset::east_opt(0).unwrap());
+    let _dt: DateTime<FixedOffset> = ndt_fixed.to_string().parse().unwrap();
+}
+
+#[test]
+#[cfg(feature = "clock")]
+fn test_to_string_round_trip_with_local() {
+    let ndt = Local::now();
+    let _dt: DateTime<FixedOffset> = ndt.to_string().parse().unwrap();
+}
+
+#[test]
+#[cfg(feature = "clock")]
+fn test_datetime_format_with_local() {
+    // if we are not around the year boundary, local and UTC date should have the same year
+    let dt = Local::now().with_month(5).unwrap();
+    assert_eq!(dt.format("%Y").to_string(), dt.with_timezone(&Utc).format("%Y").to_string());
+}
+
+#[test]
+#[cfg(feature = "clock")]
+fn test_datetime_is_copy() {
+    // UTC is known to be `Copy`.
+    let a = Utc::now();
+    let b = a;
+    assert_eq!(a, b);
+}
+
+#[test]
+#[cfg(feature = "clock")]
+fn test_datetime_is_send() {
+    use std::thread;
+
+    // UTC is known to be `Send`.
+    let a = Utc::now();
+    thread::spawn(move || {
+        let _ = a;
+    })
+    .join()
+    .unwrap();
+}
+
+#[test]
+fn test_subsecond_part() {
+    let datetime = Utc
+        .from_local_datetime(
+            &NaiveDate::from_ymd_opt(2014, 7, 8)
+                .unwrap()
+                .and_hms_nano_opt(9, 10, 11, 1234567)
+                .unwrap(),
+        )
+        .unwrap();
+
+    assert_eq!(1, datetime.timestamp_subsec_millis());
+    assert_eq!(1234, datetime.timestamp_subsec_micros());
+    assert_eq!(1234567, datetime.timestamp_subsec_nanos());
+}
+
+#[test]
+#[cfg(not(target_os = "windows"))]
+fn test_from_system_time() {
+    use std::time::Duration;
+
+    let epoch = Utc.with_ymd_and_hms(1970, 1, 1, 0, 0, 0).unwrap();
+    let nanos = 999_999_999;
+
+    // SystemTime -> DateTime<Utc>
+    assert_eq!(DateTime::<Utc>::from(UNIX_EPOCH), epoch);
+    assert_eq!(
+        DateTime::<Utc>::from(UNIX_EPOCH + Duration::new(999_999_999, nanos)),
+        Utc.from_local_datetime(
+            &NaiveDate::from_ymd_opt(2001, 9, 9)
+                .unwrap()
+                .and_hms_nano_opt(1, 46, 39, nanos)
+                .unwrap()
+        )
+        .unwrap()
+    );
+    assert_eq!(
+        DateTime::<Utc>::from(UNIX_EPOCH - Duration::new(999_999_999, nanos)),
+        Utc.from_local_datetime(
+            &NaiveDate::from_ymd_opt(1938, 4, 24).unwrap().and_hms_nano_opt(22, 13, 20, 1).unwrap()
+        )
+        .unwrap()
+    );
+
+    // DateTime<Utc> -> SystemTime
+    assert_eq!(SystemTime::from(epoch), UNIX_EPOCH);
+    assert_eq!(
+        SystemTime::from(
+            Utc.from_local_datetime(
+                &NaiveDate::from_ymd_opt(2001, 9, 9)
+                    .unwrap()
+                    .and_hms_nano_opt(1, 46, 39, nanos)
+                    .unwrap()
+            )
+            .unwrap()
+        ),
+        UNIX_EPOCH + Duration::new(999_999_999, nanos)
+    );
+    assert_eq!(
+        SystemTime::from(
+            Utc.from_local_datetime(
+                &NaiveDate::from_ymd_opt(1938, 4, 24)
+                    .unwrap()
+                    .and_hms_nano_opt(22, 13, 20, 1)
+                    .unwrap()
+            )
+            .unwrap()
+        ),
+        UNIX_EPOCH - Duration::new(999_999_999, 999_999_999)
+    );
+
+    // DateTime<any tz> -> SystemTime (via `with_timezone`)
+    #[cfg(feature = "clock")]
+    {
+        assert_eq!(SystemTime::from(epoch.with_timezone(&Local)), UNIX_EPOCH);
+    }
+    assert_eq!(
+        SystemTime::from(epoch.with_timezone(&FixedOffset::east_opt(32400).unwrap())),
+        UNIX_EPOCH
+    );
+    assert_eq!(
+        SystemTime::from(epoch.with_timezone(&FixedOffset::west_opt(28800).unwrap())),
+        UNIX_EPOCH
+    );
+}
+
+#[test]
+#[cfg(target_os = "windows")]
+fn test_from_system_time() {
+    use std::time::Duration;
+
+    let nanos = 999_999_000;
+
+    let epoch = Utc.with_ymd_and_hms(1970, 1, 1, 0, 0, 0).unwrap();
+
+    // SystemTime -> DateTime<Utc>
+    assert_eq!(DateTime::<Utc>::from(UNIX_EPOCH), epoch);
+    assert_eq!(
+        DateTime::<Utc>::from(UNIX_EPOCH + Duration::new(999_999_999, nanos)),
+        Utc.from_local_datetime(
+            &NaiveDate::from_ymd_opt(2001, 9, 9)
+                .unwrap()
+                .and_hms_nano_opt(1, 46, 39, nanos)
+                .unwrap()
+        )
+        .unwrap()
+    );
+    assert_eq!(
+        DateTime::<Utc>::from(UNIX_EPOCH - Duration::new(999_999_999, nanos)),
+        Utc.from_local_datetime(
+            &NaiveDate::from_ymd_opt(1938, 4, 24)
+                .unwrap()
+                .and_hms_nano_opt(22, 13, 20, 1_000)
+                .unwrap()
+        )
+        .unwrap()
+    );
+
+    // DateTime<Utc> -> SystemTime
+    assert_eq!(SystemTime::from(epoch), UNIX_EPOCH);
+    assert_eq!(
+        SystemTime::from(
+            Utc.from_local_datetime(
+                &NaiveDate::from_ymd_opt(2001, 9, 9)
+                    .unwrap()
+                    .and_hms_nano_opt(1, 46, 39, nanos)
+                    .unwrap()
+            )
+            .unwrap()
+        ),
+        UNIX_EPOCH + Duration::new(999_999_999, nanos)
+    );
+    assert_eq!(
+        SystemTime::from(
+            Utc.from_local_datetime(
+                &NaiveDate::from_ymd_opt(1938, 4, 24)
+                    .unwrap()
+                    .and_hms_nano_opt(22, 13, 20, 1_000)
+                    .unwrap()
+            )
+            .unwrap()
+        ),
+        UNIX_EPOCH - Duration::new(999_999_999, nanos)
+    );
+
+    // DateTime<any tz> -> SystemTime (via `with_timezone`)
+    #[cfg(feature = "clock")]
+    {
+        assert_eq!(SystemTime::from(epoch.with_timezone(&Local)), UNIX_EPOCH);
+    }
+    assert_eq!(
+        SystemTime::from(epoch.with_timezone(&FixedOffset::east_opt(32400).unwrap())),
+        UNIX_EPOCH
+    );
+    assert_eq!(
+        SystemTime::from(epoch.with_timezone(&FixedOffset::west_opt(28800).unwrap())),
+        UNIX_EPOCH
+    );
+}
+
+#[test]
+fn test_datetime_format_alignment() {
+    let datetime = Utc.with_ymd_and_hms(2007, 1, 2, 0, 0, 0).unwrap();
+
+    // Item::Literal
+    let percent = datetime.format("%%");
+    assert_eq!("  %", format!("{:>3}", percent));
+    assert_eq!("%  ", format!("{:<3}", percent));
+    assert_eq!(" % ", format!("{:^3}", percent));
+
+    // Item::Numeric
+    let year = datetime.format("%Y");
+    assert_eq!("  2007", format!("{:>6}", year));
+    assert_eq!("2007  ", format!("{:<6}", year));
+    assert_eq!(" 2007 ", format!("{:^6}", year));
+
+    // Item::Fixed
+    let tz = datetime.format("%Z");
+    assert_eq!("  UTC", format!("{:>5}", tz));
+    assert_eq!("UTC  ", format!("{:<5}", tz));
+    assert_eq!(" UTC ", format!("{:^5}", tz));
+
+    // [Item::Numeric, Item::Space, Item::Literal, Item::Space, Item::Numeric]
+    let ymd = datetime.format("%Y %B %d");
+    let ymd_formatted = "2007 January 02";
+    assert_eq!(format!("  {}", ymd_formatted), format!("{:>17}", ymd));
+    assert_eq!(format!("{}  ", ymd_formatted), format!("{:<17}", ymd));
+    assert_eq!(format!(" {} ", ymd_formatted), format!("{:^17}", ymd));
+}
+
+#[test]
+fn test_datetime_from_local() {
+    // 2000-01-12T02:00:00Z
+    let naivedatetime_utc =
+        NaiveDate::from_ymd_opt(2000, 1, 12).unwrap().and_hms_opt(2, 0, 0).unwrap();
+    let datetime_utc = DateTime::<Utc>::from_utc(naivedatetime_utc, Utc);
+
+    // 2000-01-12T10:00:00+8:00:00
+    let timezone_east = FixedOffset::east_opt(8 * 60 * 60).unwrap();
+    let naivedatetime_east =
+        NaiveDate::from_ymd_opt(2000, 1, 12).unwrap().and_hms_opt(10, 0, 0).unwrap();
+    let datetime_east = DateTime::<FixedOffset>::from_local(naivedatetime_east, timezone_east);
+
+    // 2000-01-11T19:00:00-7:00:00
+    let timezone_west = FixedOffset::west_opt(7 * 60 * 60).unwrap();
+    let naivedatetime_west =
+        NaiveDate::from_ymd_opt(2000, 1, 11).unwrap().and_hms_opt(19, 0, 0).unwrap();
+    let datetime_west = DateTime::<FixedOffset>::from_local(naivedatetime_west, timezone_west);
+
+    assert_eq!(datetime_east, datetime_utc.with_timezone(&timezone_east));
+    assert_eq!(datetime_west, datetime_utc.with_timezone(&timezone_west));
+}
+
+#[test]
+#[cfg(feature = "clock")]
+fn test_years_elapsed() {
+    const WEEKS_PER_YEAR: f32 = 52.1775;
+
+    // This is always at least one year because 1 year = 52.1775 weeks.
+    let one_year_ago =
+        Utc::now().date_naive() - Duration::weeks((WEEKS_PER_YEAR * 1.5).ceil() as i64);
+    // A bit more than 2 years.
+    let two_year_ago =
+        Utc::now().date_naive() - Duration::weeks((WEEKS_PER_YEAR * 2.5).ceil() as i64);
+
+    assert_eq!(Utc::now().date_naive().years_since(one_year_ago), Some(1));
+    assert_eq!(Utc::now().date_naive().years_since(two_year_ago), Some(2));
+
+    // If the given DateTime is later than now, the function will always return 0.
+    let future = Utc::now().date_naive() + Duration::weeks(12);
+    assert_eq!(Utc::now().date_naive().years_since(future), None);
+}
+
+#[test]
+fn test_datetime_add_assign() {
+    let naivedatetime = NaiveDate::from_ymd_opt(2000, 1, 1).unwrap().and_hms_opt(0, 0, 0).unwrap();
+    let datetime = DateTime::<Utc>::from_utc(naivedatetime, Utc);
+    let mut datetime_add = datetime;
+
+    datetime_add += Duration::seconds(60);
+    assert_eq!(datetime_add, datetime + Duration::seconds(60));
+
+    let timezone = FixedOffset::east_opt(60 * 60).unwrap();
+    let datetime = datetime.with_timezone(&timezone);
+    let datetime_add = datetime_add.with_timezone(&timezone);
+
+    assert_eq!(datetime_add, datetime + Duration::seconds(60));
+
+    let timezone = FixedOffset::west_opt(2 * 60 * 60).unwrap();
+    let datetime = datetime.with_timezone(&timezone);
+    let datetime_add = datetime_add.with_timezone(&timezone);
+
+    assert_eq!(datetime_add, datetime + Duration::seconds(60));
+}
+
+#[test]
+#[cfg(feature = "clock")]
+fn test_datetime_add_assign_local() {
+    let naivedatetime = NaiveDate::from_ymd_opt(2022, 1, 1).unwrap().and_hms_opt(0, 0, 0).unwrap();
+
+    let datetime = Local.from_utc_datetime(&naivedatetime);
+    let mut datetime_add = Local.from_utc_datetime(&naivedatetime);
+
+    // ensure we cross a DST transition
+    for i in 1..=365 {
+        datetime_add += Duration::days(1);
+        assert_eq!(datetime_add, datetime + Duration::days(i))
+    }
+}
+
+#[test]
+fn test_datetime_sub_assign() {
+    let naivedatetime = NaiveDate::from_ymd_opt(2000, 1, 1).unwrap().and_hms_opt(12, 0, 0).unwrap();
+    let datetime = DateTime::<Utc>::from_utc(naivedatetime, Utc);
+    let mut datetime_sub = datetime;
+
+    datetime_sub -= Duration::minutes(90);
+    assert_eq!(datetime_sub, datetime - Duration::minutes(90));
+
+    let timezone = FixedOffset::east_opt(60 * 60).unwrap();
+    let datetime = datetime.with_timezone(&timezone);
+    let datetime_sub = datetime_sub.with_timezone(&timezone);
+
+    assert_eq!(datetime_sub, datetime - Duration::minutes(90));
+
+    let timezone = FixedOffset::west_opt(2 * 60 * 60).unwrap();
+    let datetime = datetime.with_timezone(&timezone);
+    let datetime_sub = datetime_sub.with_timezone(&timezone);
+
+    assert_eq!(datetime_sub, datetime - Duration::minutes(90));
+}
+
+#[test]
+#[cfg(feature = "clock")]
+fn test_datetime_sub_assign_local() {
+    let naivedatetime = NaiveDate::from_ymd_opt(2022, 1, 1).unwrap().and_hms_opt(0, 0, 0).unwrap();
+
+    let datetime = Local.from_utc_datetime(&naivedatetime);
+    let mut datetime_sub = Local.from_utc_datetime(&naivedatetime);
+
+    // ensure we cross a DST transition
+    for i in 1..=365 {
+        datetime_sub -= Duration::days(1);
+        assert_eq!(datetime_sub, datetime - Duration::days(i))
+    }
+}

javascript-engine/external/chrono/src/format/locales.rs

@@ -0,0 +1,33 @@
+use pure_rust_locales::{locale_match, Locale};
+
+pub(crate) fn short_months(locale: Locale) -> &'static [&'static str] {
+    locale_match!(locale => LC_TIME::ABMON)
+}
+
+pub(crate) fn long_months(locale: Locale) -> &'static [&'static str] {
+    locale_match!(locale => LC_TIME::MON)
+}
+
+pub(crate) fn short_weekdays(locale: Locale) -> &'static [&'static str] {
+    locale_match!(locale => LC_TIME::ABDAY)
+}
+
+pub(crate) fn long_weekdays(locale: Locale) -> &'static [&'static str] {
+    locale_match!(locale => LC_TIME::DAY)
+}
+
+pub(crate) fn am_pm(locale: Locale) -> &'static [&'static str] {
+    locale_match!(locale => LC_TIME::AM_PM)
+}
+
+pub(crate) fn d_fmt(locale: Locale) -> &'static str {
+    locale_match!(locale => LC_TIME::D_FMT)
+}
+
+pub(crate) fn d_t_fmt(locale: Locale) -> &'static str {
+    locale_match!(locale => LC_TIME::D_T_FMT)
+}
+
+pub(crate) fn t_fmt(locale: Locale) -> &'static str {
+    locale_match!(locale => LC_TIME::T_FMT)
+}

javascript-engine/external/chrono/src/format/parse.rs

@@ -0,0 +1,977 @@
+// This is a part of Chrono.
+// Portions copyright (c) 2015, John Nagle.
+// See README.md and LICENSE.txt for details.
+
+//! Date and time parsing routines.
+
+#![allow(deprecated)]
+
+use core::borrow::Borrow;
+use core::str;
+use core::usize;
+
+use super::scan;
+use super::{Fixed, InternalFixed, InternalInternal, Item, Numeric, Pad, Parsed};
+use super::{ParseError, ParseErrorKind, ParseResult};
+use super::{BAD_FORMAT, INVALID, NOT_ENOUGH, OUT_OF_RANGE, TOO_LONG, TOO_SHORT};
+use crate::{DateTime, FixedOffset, Weekday};
+
+fn set_weekday_with_num_days_from_sunday(p: &mut Parsed, v: i64) -> ParseResult<()> {
+    p.set_weekday(match v {
+        0 => Weekday::Sun,
+        1 => Weekday::Mon,
+        2 => Weekday::Tue,
+        3 => Weekday::Wed,
+        4 => Weekday::Thu,
+        5 => Weekday::Fri,
+        6 => Weekday::Sat,
+        _ => return Err(OUT_OF_RANGE),
+    })
+}
+
+fn set_weekday_with_number_from_monday(p: &mut Parsed, v: i64) -> ParseResult<()> {
+    p.set_weekday(match v {
+        1 => Weekday::Mon,
+        2 => Weekday::Tue,
+        3 => Weekday::Wed,
+        4 => Weekday::Thu,
+        5 => Weekday::Fri,
+        6 => Weekday::Sat,
+        7 => Weekday::Sun,
+        _ => return Err(OUT_OF_RANGE),
+    })
+}
+
+fn parse_rfc2822<'a>(parsed: &mut Parsed, mut s: &'a str) -> ParseResult<(&'a str, ())> {
+    macro_rules! try_consume {
+        ($e:expr) => {{
+            let (s_, v) = $e?;
+            s = s_;
+            v
+        }};
+    }
+
+    // an adapted RFC 2822 syntax from Section 3.3 and 4.3:
+    //
+    // c-char      = <any char except '(', ')' and '\\'>
+    // c-escape    = "\" <any char>
+    // comment     = "(" *(comment / c-char / c-escape) ")" *S
+    // date-time   = [ day-of-week "," ] date 1*S time *S *comment
+    // day-of-week = *S day-name *S
+    // day-name    = "Mon" / "Tue" / "Wed" / "Thu" / "Fri" / "Sat" / "Sun"
+    // date        = day month year
+    // day         = *S 1*2DIGIT *S
+    // month       = 1*S month-name 1*S
+    // month-name  = "Jan" / "Feb" / "Mar" / "Apr" / "May" / "Jun" /
+    //               "Jul" / "Aug" / "Sep" / "Oct" / "Nov" / "Dec"
+    // year        = *S 2*DIGIT *S
+    // time        = time-of-day 1*S zone
+    // time-of-day = hour ":" minute [ ":" second ]
+    // hour        = *S 2DIGIT *S
+    // minute      = *S 2DIGIT *S
+    // second      = *S 2DIGIT *S
+    // zone        = ( "+" / "-" ) 4DIGIT /
+    //               "UT" / "GMT" /                  ; same as +0000
+    //               "EST" / "CST" / "MST" / "PST" / ; same as -0500 to -0800
+    //               "EDT" / "CDT" / "MDT" / "PDT" / ; same as -0400 to -0700
+    //               1*(%d65-90 / %d97-122)          ; same as -0000
+    //
+    // some notes:
+    //
+    // - quoted characters can be in any mixture of lower and upper cases.
+    //
+    // - we do not recognize a folding white space (FWS) or comment (CFWS).
+    //   for our purposes, instead, we accept any sequence of Unicode
+    //   white space characters (denoted here to `S`). For comments, we accept
+    //   any text within parentheses while respecting escaped parentheses.
+    //   Any actual RFC 2822 parser is expected to parse FWS and/or CFWS themselves
+    //   and replace it with a single SP (`%x20`); this is legitimate.
+    //
+    // - two-digit year < 50 should be interpreted by adding 2000.
+    //   two-digit year >= 50 or three-digit year should be interpreted
+    //   by adding 1900. note that four-or-more-digit years less than 1000
+    //   are *never* affected by this rule.
+    //
+    // - mismatching day-of-week is always an error, which is consistent to
+    //   Chrono's own rules.
+    //
+    // - zones can range from `-9959` to `+9959`, but `FixedOffset` does not
+    //   support offsets larger than 24 hours. this is not *that* problematic
+    //   since we do not directly go to a `DateTime` so one can recover
+    //   the offset information from `Parsed` anyway.
+
+    s = s.trim_left();
+
+    if let Ok((s_, weekday)) = scan::short_weekday(s) {
+        if !s_.starts_with(',') {
+            return Err(INVALID);
+        }
+        s = &s_[1..];
+        parsed.set_weekday(weekday)?;
+    }
+
+    s = s.trim_left();
+    parsed.set_day(try_consume!(scan::number(s, 1, 2)))?;
+    s = scan::space(s)?; // mandatory
+    parsed.set_month(1 + i64::from(try_consume!(scan::short_month0(s))))?;
+    s = scan::space(s)?; // mandatory
+
+    // distinguish two- and three-digit years from four-digit years
+    let prevlen = s.len();
+    let mut year = try_consume!(scan::number(s, 2, usize::MAX));
+    let yearlen = prevlen - s.len();
+    match (yearlen, year) {
+        (2, 0..=49) => {
+            year += 2000;
+        } //   47 -> 2047,   05 -> 2005
+        (2, 50..=99) => {
+            year += 1900;
+        } //   79 -> 1979
+        (3, _) => {
+            year += 1900;
+        } //  112 -> 2012,  009 -> 1909
+        (_, _) => {} // 1987 -> 1987, 0654 -> 0654
+    }
+    parsed.set_year(year)?;
+
+    s = scan::space(s)?; // mandatory
+    parsed.set_hour(try_consume!(scan::number(s, 2, 2)))?;
+    s = scan::char(s.trim_left(), b':')?.trim_left(); // *S ":" *S
+    parsed.set_minute(try_consume!(scan::number(s, 2, 2)))?;
+    if let Ok(s_) = scan::char(s.trim_left(), b':') {
+        // [ ":" *S 2DIGIT ]
+        parsed.set_second(try_consume!(scan::number(s_, 2, 2)))?;
+    }
+
+    s = scan::space(s)?; // mandatory
+    if let Some(offset) = try_consume!(scan::timezone_offset_2822(s)) {
+        // only set the offset when it is definitely known (i.e. not `-0000`)
+        parsed.set_offset(i64::from(offset))?;
+    }
+
+    // optional comments
+    while let Ok((s_out, ())) = scan::comment_2822(s) {
+        s = s_out;
+    }
+
+    Ok((s, ()))
+}
+
+fn parse_rfc3339<'a>(parsed: &mut Parsed, mut s: &'a str) -> ParseResult<(&'a str, ())> {
+    macro_rules! try_consume {
+        ($e:expr) => {{
+            let (s_, v) = $e?;
+            s = s_;
+            v
+        }};
+    }
+
+    // an adapted RFC 3339 syntax from Section 5.6:
+    //
+    // date-fullyear  = 4DIGIT
+    // date-month     = 2DIGIT ; 01-12
+    // date-mday      = 2DIGIT ; 01-28, 01-29, 01-30, 01-31 based on month/year
+    // time-hour      = 2DIGIT ; 00-23
+    // time-minute    = 2DIGIT ; 00-59
+    // time-second    = 2DIGIT ; 00-58, 00-59, 00-60 based on leap second rules
+    // time-secfrac   = "." 1*DIGIT
+    // time-numoffset = ("+" / "-") time-hour ":" time-minute
+    // time-offset    = "Z" / time-numoffset
+    // partial-time   = time-hour ":" time-minute ":" time-second [time-secfrac]
+    // full-date      = date-fullyear "-" date-month "-" date-mday
+    // full-time      = partial-time time-offset
+    // date-time      = full-date "T" full-time
+    //
+    // some notes:
+    //
+    // - quoted characters can be in any mixture of lower and upper cases.
+    //
+    // - it may accept any number of fractional digits for seconds.
+    //   for Chrono, this means that we should skip digits past first 9 digits.
+    //
+    // - unlike RFC 2822, the valid offset ranges from -23:59 to +23:59.
+    //   note that this restriction is unique to RFC 3339 and not ISO 8601.
+    //   since this is not a typical Chrono behavior, we check it earlier.
+
+    parsed.set_year(try_consume!(scan::number(s, 4, 4)))?;
+    s = scan::char(s, b'-')?;
+    parsed.set_month(try_consume!(scan::number(s, 2, 2)))?;
+    s = scan::char(s, b'-')?;
+    parsed.set_day(try_consume!(scan::number(s, 2, 2)))?;
+
+    s = match s.as_bytes().first() {
+        Some(&b't') | Some(&b'T') => &s[1..],
+        Some(_) => return Err(INVALID),
+        None => return Err(TOO_SHORT),
+    };
+
+    parsed.set_hour(try_consume!(scan::number(s, 2, 2)))?;
+    s = scan::char(s, b':')?;
+    parsed.set_minute(try_consume!(scan::number(s, 2, 2)))?;
+    s = scan::char(s, b':')?;
+    parsed.set_second(try_consume!(scan::number(s, 2, 2)))?;
+    if s.starts_with('.') {
+        let nanosecond = try_consume!(scan::nanosecond(&s[1..]));
+        parsed.set_nanosecond(nanosecond)?;
+    }
+
+    let offset = try_consume!(scan::timezone_offset_zulu(s, |s| scan::char(s, b':')));
+    if offset <= -86_400 || offset >= 86_400 {
+        return Err(OUT_OF_RANGE);
+    }
+    parsed.set_offset(i64::from(offset))?;
+
+    Ok((s, ()))
+}
+
+/// Tries to parse given string into `parsed` with given formatting items.
+/// Returns `Ok` when the entire string has been parsed (otherwise `parsed` should not be used).
+/// There should be no trailing string after parsing;
+/// use a stray [`Item::Space`](./enum.Item.html#variant.Space) to trim whitespaces.
+///
+/// This particular date and time parser is:
+///
+/// - Greedy. It will consume the longest possible prefix.
+///   For example, `April` is always consumed entirely when the long month name is requested;
+///   it equally accepts `Apr`, but prefers the longer prefix in this case.
+///
+/// - Padding-agnostic (for numeric items).
+///   The [`Pad`](./enum.Pad.html) field is completely ignored,
+///   so one can prepend any number of whitespace then any number of zeroes before numbers.
+///
+/// - (Still) obeying the intrinsic parsing width. This allows, for example, parsing `HHMMSS`.
+pub fn parse<'a, I, B>(parsed: &mut Parsed, s: &str, items: I) -> ParseResult<()>
+where
+    I: Iterator<Item = B>,
+    B: Borrow<Item<'a>>,
+{
+    parse_internal(parsed, s, items).map(|_| ()).map_err(|(_s, e)| e)
+}
+
+fn parse_internal<'a, 'b, I, B>(
+    parsed: &mut Parsed,
+    mut s: &'b str,
+    items: I,
+) -> Result<&'b str, (&'b str, ParseError)>
+where
+    I: Iterator<Item = B>,
+    B: Borrow<Item<'a>>,
+{
+    macro_rules! try_consume {
+        ($e:expr) => {{
+            match $e {
+                Ok((s_, v)) => {
+                    s = s_;
+                    v
+                }
+                Err(e) => return Err((s, e)),
+            }
+        }};
+    }
+
+    for item in items {
+        match *item.borrow() {
+            Item::Literal(prefix) => {
+                if s.len() < prefix.len() {
+                    return Err((s, TOO_SHORT));
+                }
+                if !s.starts_with(prefix) {
+                    return Err((s, INVALID));
+                }
+                s = &s[prefix.len()..];
+            }
+
+            #[cfg(any(feature = "alloc", feature = "std", test))]
+            Item::OwnedLiteral(ref prefix) => {
+                if s.len() < prefix.len() {
+                    return Err((s, TOO_SHORT));
+                }
+                if !s.starts_with(&prefix[..]) {
+                    return Err((s, INVALID));
+                }
+                s = &s[prefix.len()..];
+            }
+
+            Item::Space(_) => {
+                s = s.trim_left();
+            }
+
+            #[cfg(any(feature = "alloc", feature = "std", test))]
+            Item::OwnedSpace(_) => {
+                s = s.trim_left();
+            }
+
+            Item::Numeric(ref spec, ref _pad) => {
+                use super::Numeric::*;
+                type Setter = fn(&mut Parsed, i64) -> ParseResult<()>;
+
+                let (width, signed, set): (usize, bool, Setter) = match *spec {
+                    Year => (4, true, Parsed::set_year),
+                    YearDiv100 => (2, false, Parsed::set_year_div_100),
+                    YearMod100 => (2, false, Parsed::set_year_mod_100),
+                    IsoYear => (4, true, Parsed::set_isoyear),
+                    IsoYearDiv100 => (2, false, Parsed::set_isoyear_div_100),
+                    IsoYearMod100 => (2, false, Parsed::set_isoyear_mod_100),
+                    Month => (2, false, Parsed::set_month),
+                    Day => (2, false, Parsed::set_day),
+                    WeekFromSun => (2, false, Parsed::set_week_from_sun),
+                    WeekFromMon => (2, false, Parsed::set_week_from_mon),
+                    IsoWeek => (2, false, Parsed::set_isoweek),
+                    NumDaysFromSun => (1, false, set_weekday_with_num_days_from_sunday),
+                    WeekdayFromMon => (1, false, set_weekday_with_number_from_monday),
+                    Ordinal => (3, false, Parsed::set_ordinal),
+                    Hour => (2, false, Parsed::set_hour),
+                    Hour12 => (2, false, Parsed::set_hour12),
+                    Minute => (2, false, Parsed::set_minute),
+                    Second => (2, false, Parsed::set_second),
+                    Nanosecond => (9, false, Parsed::set_nanosecond),
+                    Timestamp => (usize::MAX, false, Parsed::set_timestamp),
+
+                    // for the future expansion
+                    Internal(ref int) => match int._dummy {},
+                };
+
+                s = s.trim_left();
+                let v = if signed {
+                    if s.starts_with('-') {
+                        let v = try_consume!(scan::number(&s[1..], 1, usize::MAX));
+                        0i64.checked_sub(v).ok_or((s, OUT_OF_RANGE))?
+                    } else if s.starts_with('+') {
+                        try_consume!(scan::number(&s[1..], 1, usize::MAX))
+                    } else {
+                        // if there is no explicit sign, we respect the original `width`
+                        try_consume!(scan::number(s, 1, width))
+                    }
+                } else {
+                    try_consume!(scan::number(s, 1, width))
+                };
+                set(parsed, v).map_err(|e| (s, e))?;
+            }
+
+            Item::Fixed(ref spec) => {
+                use super::Fixed::*;
+
+                match spec {
+                    &ShortMonthName => {
+                        let month0 = try_consume!(scan::short_month0(s));
+                        parsed.set_month(i64::from(month0) + 1).map_err(|e| (s, e))?;
+                    }
+
+                    &LongMonthName => {
+                        let month0 = try_consume!(scan::short_or_long_month0(s));
+                        parsed.set_month(i64::from(month0) + 1).map_err(|e| (s, e))?;
+                    }
+
+                    &ShortWeekdayName => {
+                        let weekday = try_consume!(scan::short_weekday(s));
+                        parsed.set_weekday(weekday).map_err(|e| (s, e))?;
+                    }
+
+                    &LongWeekdayName => {
+                        let weekday = try_consume!(scan::short_or_long_weekday(s));
+                        parsed.set_weekday(weekday).map_err(|e| (s, e))?;
+                    }
+
+                    &LowerAmPm | &UpperAmPm => {
+                        if s.len() < 2 {
+                            return Err((s, TOO_SHORT));
+                        }
+                        let ampm = match (s.as_bytes()[0] | 32, s.as_bytes()[1] | 32) {
+                            (b'a', b'm') => false,
+                            (b'p', b'm') => true,
+                            _ => return Err((s, INVALID)),
+                        };
+                        parsed.set_ampm(ampm).map_err(|e| (s, e))?;
+                        s = &s[2..];
+                    }
+
+                    &Nanosecond | &Nanosecond3 | &Nanosecond6 | &Nanosecond9 => {
+                        if s.starts_with('.') {
+                            let nano = try_consume!(scan::nanosecond(&s[1..]));
+                            parsed.set_nanosecond(nano).map_err(|e| (s, e))?;
+                        }
+                    }
+
+                    &Internal(InternalFixed { val: InternalInternal::Nanosecond3NoDot }) => {
+                        if s.len() < 3 {
+                            return Err((s, TOO_SHORT));
+                        }
+                        let nano = try_consume!(scan::nanosecond_fixed(s, 3));
+                        parsed.set_nanosecond(nano).map_err(|e| (s, e))?;
+                    }
+
+                    &Internal(InternalFixed { val: InternalInternal::Nanosecond6NoDot }) => {
+                        if s.len() < 6 {
+                            return Err((s, TOO_SHORT));
+                        }
+                        let nano = try_consume!(scan::nanosecond_fixed(s, 6));
+                        parsed.set_nanosecond(nano).map_err(|e| (s, e))?;
+                    }
+
+                    &Internal(InternalFixed { val: InternalInternal::Nanosecond9NoDot }) => {
+                        if s.len() < 9 {
+                            return Err((s, TOO_SHORT));
+                        }
+                        let nano = try_consume!(scan::nanosecond_fixed(s, 9));
+                        parsed.set_nanosecond(nano).map_err(|e| (s, e))?;
+                    }
+
+                    &TimezoneName => {
+                        try_consume!(scan::timezone_name_skip(s));
+                    }
+
+                    &TimezoneOffsetColon
+                    | &TimezoneOffsetDoubleColon
+                    | &TimezoneOffsetTripleColon
+                    | &TimezoneOffset => {
+                        let offset = try_consume!(scan::timezone_offset(
+                            s.trim_left(),
+                            scan::colon_or_space
+                        ));
+                        parsed.set_offset(i64::from(offset)).map_err(|e| (s, e))?;
+                    }
+
+                    &TimezoneOffsetColonZ | &TimezoneOffsetZ => {
+                        let offset = try_consume!(scan::timezone_offset_zulu(
+                            s.trim_left(),
+                            scan::colon_or_space
+                        ));
+                        parsed.set_offset(i64::from(offset)).map_err(|e| (s, e))?;
+                    }
+                    &Internal(InternalFixed {
+                        val: InternalInternal::TimezoneOffsetPermissive,
+                    }) => {
+                        let offset = try_consume!(scan::timezone_offset_permissive(
+                            s.trim_left(),
+                            scan::colon_or_space
+                        ));
+                        parsed.set_offset(i64::from(offset)).map_err(|e| (s, e))?;
+                    }
+
+                    &RFC2822 => try_consume!(parse_rfc2822(parsed, s)),
+                    &RFC3339 => try_consume!(parse_rfc3339(parsed, s)),
+                }
+            }
+
+            Item::Error => {
+                return Err((s, BAD_FORMAT));
+            }
+        }
+    }
+
+    // if there are trailling chars, it is an error
+    if !s.is_empty() {
+        Err((s, TOO_LONG))
+    } else {
+        Ok(s)
+    }
+}
+
+/// Accepts a relaxed form of RFC3339.
+/// A space or a 'T' are acepted as the separator between the date and time
+/// parts. Additional spaces are allowed between each component.
+///
+/// All of these examples are equivalent:
+/// ```
+/// # use chrono::{DateTime, offset::FixedOffset};
+/// "2012-12-12T12:12:12Z".parse::<DateTime<FixedOffset>>();
+/// "2012-12-12 12:12:12Z".parse::<DateTime<FixedOffset>>();
+/// "2012-  12-12T12:  12:12Z".parse::<DateTime<FixedOffset>>();
+/// ```
+impl str::FromStr for DateTime<FixedOffset> {
+    type Err = ParseError;
+
+    fn from_str(s: &str) -> ParseResult<DateTime<FixedOffset>> {
+        const DATE_ITEMS: &[Item<'static>] = &[
+            Item::Numeric(Numeric::Year, Pad::Zero),
+            Item::Space(""),
+            Item::Literal("-"),
+            Item::Numeric(Numeric::Month, Pad::Zero),
+            Item::Space(""),
+            Item::Literal("-"),
+            Item::Numeric(Numeric::Day, Pad::Zero),
+        ];
+        const TIME_ITEMS: &[Item<'static>] = &[
+            Item::Numeric(Numeric::Hour, Pad::Zero),
+            Item::Space(""),
+            Item::Literal(":"),
+            Item::Numeric(Numeric::Minute, Pad::Zero),
+            Item::Space(""),
+            Item::Literal(":"),
+            Item::Numeric(Numeric::Second, Pad::Zero),
+            Item::Fixed(Fixed::Nanosecond),
+            Item::Space(""),
+            Item::Fixed(Fixed::TimezoneOffsetZ),
+            Item::Space(""),
+        ];
+
+        let mut parsed = Parsed::new();
+        match parse_internal(&mut parsed, s, DATE_ITEMS.iter()) {
+            Err((remainder, e)) if e.0 == ParseErrorKind::TooLong => {
+                if remainder.starts_with('T') || remainder.starts_with(' ') {
+                    parse(&mut parsed, &remainder[1..], TIME_ITEMS.iter())?;
+                } else {
+                    return Err(INVALID);
+                }
+            }
+            Err((_s, e)) => return Err(e),
+            Ok(_) => return Err(NOT_ENOUGH),
+        };
+        parsed.to_datetime()
+    }
+}
+
+#[cfg(test)]
+#[test]
+fn test_parse() {
+    use super::IMPOSSIBLE;
+    use super::*;
+
+    // workaround for Rust issue #22255
+    fn parse_all(s: &str, items: &[Item]) -> ParseResult<Parsed> {
+        let mut parsed = Parsed::new();
+        parse(&mut parsed, s, items.iter())?;
+        Ok(parsed)
+    }
+
+    macro_rules! check {
+        ($fmt:expr, $items:expr; $err:tt) => (
+            assert_eq!(parse_all($fmt, &$items), Err($err))
+        );
+        ($fmt:expr, $items:expr; $($k:ident: $v:expr),*) => (#[allow(unused_mut)] {
+            let mut expected = Parsed::new();
+            $(expected.$k = Some($v);)*
+            assert_eq!(parse_all($fmt, &$items), Ok(expected))
+        });
+    }
+
+    // empty string
+    check!("",  []; );
+    check!(" ", []; TOO_LONG);
+    check!("a", []; TOO_LONG);
+
+    // whitespaces
+    check!("",          [sp!("")]; );
+    check!(" ",         [sp!("")]; );
+    check!("\t",        [sp!("")]; );
+    check!(" \n\r  \n", [sp!("")]; );
+    check!("a",         [sp!("")]; TOO_LONG);
+
+    // literal
+    check!("",    [lit!("a")]; TOO_SHORT);
+    check!(" ",   [lit!("a")]; INVALID);
+    check!("a",   [lit!("a")]; );
+    check!("aa",  [lit!("a")]; TOO_LONG);
+    check!("A",   [lit!("a")]; INVALID);
+    check!("xy",  [lit!("xy")]; );
+    check!("xy",  [lit!("x"), lit!("y")]; );
+    check!("x y", [lit!("x"), lit!("y")]; INVALID);
+    check!("xy",  [lit!("x"), sp!(""), lit!("y")]; );
+    check!("x y", [lit!("x"), sp!(""), lit!("y")]; );
+
+    // numeric
+    check!("1987",        [num!(Year)]; year: 1987);
+    check!("1987 ",       [num!(Year)]; TOO_LONG);
+    check!("0x12",        [num!(Year)]; TOO_LONG); // `0` is parsed
+    check!("x123",        [num!(Year)]; INVALID);
+    check!("2015",        [num!(Year)]; year: 2015);
+    check!("0000",        [num!(Year)]; year:    0);
+    check!("9999",        [num!(Year)]; year: 9999);
+    check!(" \t987",      [num!(Year)]; year:  987);
+    check!("5",           [num!(Year)]; year:    5);
+    check!("5\0",         [num!(Year)]; TOO_LONG);
+    check!("\x005",       [num!(Year)]; INVALID);
+    check!("",            [num!(Year)]; TOO_SHORT);
+    check!("12345",       [num!(Year), lit!("5")]; year: 1234);
+    check!("12345",       [nums!(Year), lit!("5")]; year: 1234);
+    check!("12345",       [num0!(Year), lit!("5")]; year: 1234);
+    check!("12341234",    [num!(Year), num!(Year)]; year: 1234);
+    check!("1234 1234",   [num!(Year), num!(Year)]; year: 1234);
+    check!("1234 1235",   [num!(Year), num!(Year)]; IMPOSSIBLE);
+    check!("1234 1234",   [num!(Year), lit!("x"), num!(Year)]; INVALID);
+    check!("1234x1234",   [num!(Year), lit!("x"), num!(Year)]; year: 1234);
+    check!("1234xx1234",  [num!(Year), lit!("x"), num!(Year)]; INVALID);
+    check!("1234 x 1234", [num!(Year), lit!("x"), num!(Year)]; INVALID);
+
+    // signed numeric
+    check!("-42",         [num!(Year)]; year: -42);
+    check!("+42",         [num!(Year)]; year: 42);
+    check!("-0042",       [num!(Year)]; year: -42);
+    check!("+0042",       [num!(Year)]; year: 42);
+    check!("-42195",      [num!(Year)]; year: -42195);
+    check!("+42195",      [num!(Year)]; year: 42195);
+    check!("  -42195",    [num!(Year)]; year: -42195);
+    check!("  +42195",    [num!(Year)]; year: 42195);
+    check!("  -   42",    [num!(Year)]; INVALID);
+    check!("  +   42",    [num!(Year)]; INVALID);
+    check!("-",           [num!(Year)]; TOO_SHORT);
+    check!("+",           [num!(Year)]; TOO_SHORT);
+
+    // unsigned numeric
+    check!("345",   [num!(Ordinal)]; ordinal: 345);
+    check!("+345",  [num!(Ordinal)]; INVALID);
+    check!("-345",  [num!(Ordinal)]; INVALID);
+    check!(" 345",  [num!(Ordinal)]; ordinal: 345);
+    check!(" +345", [num!(Ordinal)]; INVALID);
+    check!(" -345", [num!(Ordinal)]; INVALID);
+
+    // various numeric fields
+    check!("1234 5678",
+           [num!(Year), num!(IsoYear)];
+           year: 1234, isoyear: 5678);
+    check!("12 34 56 78",
+           [num!(YearDiv100), num!(YearMod100), num!(IsoYearDiv100), num!(IsoYearMod100)];
+           year_div_100: 12, year_mod_100: 34, isoyear_div_100: 56, isoyear_mod_100: 78);
+    check!("1 2 3 4 5 6",
+           [num!(Month), num!(Day), num!(WeekFromSun), num!(WeekFromMon), num!(IsoWeek),
+            num!(NumDaysFromSun)];
+           month: 1, day: 2, week_from_sun: 3, week_from_mon: 4, isoweek: 5, weekday: Weekday::Sat);
+    check!("7 89 01",
+           [num!(WeekdayFromMon), num!(Ordinal), num!(Hour12)];
+           weekday: Weekday::Sun, ordinal: 89, hour_mod_12: 1);
+    check!("23 45 6 78901234 567890123",
+           [num!(Hour), num!(Minute), num!(Second), num!(Nanosecond), num!(Timestamp)];
+           hour_div_12: 1, hour_mod_12: 11, minute: 45, second: 6, nanosecond: 78_901_234,
+           timestamp: 567_890_123);
+
+    // fixed: month and weekday names
+    check!("apr",       [fix!(ShortMonthName)]; month: 4);
+    check!("Apr",       [fix!(ShortMonthName)]; month: 4);
+    check!("APR",       [fix!(ShortMonthName)]; month: 4);
+    check!("ApR",       [fix!(ShortMonthName)]; month: 4);
+    check!("April",     [fix!(ShortMonthName)]; TOO_LONG); // `Apr` is parsed
+    check!("A",         [fix!(ShortMonthName)]; TOO_SHORT);
+    check!("Sol",       [fix!(ShortMonthName)]; INVALID);
+    check!("Apr",       [fix!(LongMonthName)]; month: 4);
+    check!("Apri",      [fix!(LongMonthName)]; TOO_LONG); // `Apr` is parsed
+    check!("April",     [fix!(LongMonthName)]; month: 4);
+    check!("Aprill",    [fix!(LongMonthName)]; TOO_LONG);
+    check!("Aprill",    [fix!(LongMonthName), lit!("l")]; month: 4);
+    check!("Aprl",      [fix!(LongMonthName), lit!("l")]; month: 4);
+    check!("April",     [fix!(LongMonthName), lit!("il")]; TOO_SHORT); // do not backtrack
+    check!("thu",       [fix!(ShortWeekdayName)]; weekday: Weekday::Thu);
+    check!("Thu",       [fix!(ShortWeekdayName)]; weekday: Weekday::Thu);
+    check!("THU",       [fix!(ShortWeekdayName)]; weekday: Weekday::Thu);
+    check!("tHu",       [fix!(ShortWeekdayName)]; weekday: Weekday::Thu);
+    check!("Thursday",  [fix!(ShortWeekdayName)]; TOO_LONG); // `Thu` is parsed
+    check!("T",         [fix!(ShortWeekdayName)]; TOO_SHORT);
+    check!("The",       [fix!(ShortWeekdayName)]; INVALID);
+    check!("Nop",       [fix!(ShortWeekdayName)]; INVALID);
+    check!("Thu",       [fix!(LongWeekdayName)]; weekday: Weekday::Thu);
+    check!("Thur",      [fix!(LongWeekdayName)]; TOO_LONG); // `Thu` is parsed
+    check!("Thurs",     [fix!(LongWeekdayName)]; TOO_LONG); // ditto
+    check!("Thursday",  [fix!(LongWeekdayName)]; weekday: Weekday::Thu);
+    check!("Thursdays", [fix!(LongWeekdayName)]; TOO_LONG);
+    check!("Thursdays", [fix!(LongWeekdayName), lit!("s")]; weekday: Weekday::Thu);
+    check!("Thus",      [fix!(LongWeekdayName), lit!("s")]; weekday: Weekday::Thu);
+    check!("Thursday",  [fix!(LongWeekdayName), lit!("rsday")]; TOO_SHORT); // do not backtrack
+
+    // fixed: am/pm
+    check!("am",  [fix!(LowerAmPm)]; hour_div_12: 0);
+    check!("pm",  [fix!(LowerAmPm)]; hour_div_12: 1);
+    check!("AM",  [fix!(LowerAmPm)]; hour_div_12: 0);
+    check!("PM",  [fix!(LowerAmPm)]; hour_div_12: 1);
+    check!("am",  [fix!(UpperAmPm)]; hour_div_12: 0);
+    check!("pm",  [fix!(UpperAmPm)]; hour_div_12: 1);
+    check!("AM",  [fix!(UpperAmPm)]; hour_div_12: 0);
+    check!("PM",  [fix!(UpperAmPm)]; hour_div_12: 1);
+    check!("Am",  [fix!(LowerAmPm)]; hour_div_12: 0);
+    check!(" Am", [fix!(LowerAmPm)]; INVALID);
+    check!("ame", [fix!(LowerAmPm)]; TOO_LONG); // `am` is parsed
+    check!("a",   [fix!(LowerAmPm)]; TOO_SHORT);
+    check!("p",   [fix!(LowerAmPm)]; TOO_SHORT);
+    check!("x",   [fix!(LowerAmPm)]; TOO_SHORT);
+    check!("xx",  [fix!(LowerAmPm)]; INVALID);
+    check!("",    [fix!(LowerAmPm)]; TOO_SHORT);
+
+    // fixed: dot plus nanoseconds
+    check!("",              [fix!(Nanosecond)]; ); // no field set, but not an error
+    check!("4",             [fix!(Nanosecond)]; TOO_LONG); // never consumes `4`
+    check!("4",             [fix!(Nanosecond), num!(Second)]; second: 4);
+    check!(".0",            [fix!(Nanosecond)]; nanosecond: 0);
+    check!(".4",            [fix!(Nanosecond)]; nanosecond: 400_000_000);
+    check!(".42",           [fix!(Nanosecond)]; nanosecond: 420_000_000);
+    check!(".421",          [fix!(Nanosecond)]; nanosecond: 421_000_000);
+    check!(".42195",        [fix!(Nanosecond)]; nanosecond: 421_950_000);
+    check!(".421950803",    [fix!(Nanosecond)]; nanosecond: 421_950_803);
+    check!(".421950803547", [fix!(Nanosecond)]; nanosecond: 421_950_803);
+    check!(".000000003547", [fix!(Nanosecond)]; nanosecond: 3);
+    check!(".000000000547", [fix!(Nanosecond)]; nanosecond: 0);
+    check!(".",             [fix!(Nanosecond)]; TOO_SHORT);
+    check!(".4x",           [fix!(Nanosecond)]; TOO_LONG);
+    check!(".  4",          [fix!(Nanosecond)]; INVALID);
+    check!("  .4",          [fix!(Nanosecond)]; TOO_LONG); // no automatic trimming
+
+    // fixed: nanoseconds without the dot
+    check!("",             [internal_fix!(Nanosecond3NoDot)]; TOO_SHORT);
+    check!("0",            [internal_fix!(Nanosecond3NoDot)]; TOO_SHORT);
+    check!("4",            [internal_fix!(Nanosecond3NoDot)]; TOO_SHORT);
+    check!("42",           [internal_fix!(Nanosecond3NoDot)]; TOO_SHORT);
+    check!("421",          [internal_fix!(Nanosecond3NoDot)]; nanosecond: 421_000_000);
+    check!("42143",        [internal_fix!(Nanosecond3NoDot), num!(Second)]; nanosecond: 421_000_000, second: 43);
+    check!("42195",        [internal_fix!(Nanosecond3NoDot)]; TOO_LONG);
+    check!("4x",           [internal_fix!(Nanosecond3NoDot)]; TOO_SHORT);
+    check!("  4",          [internal_fix!(Nanosecond3NoDot)]; INVALID);
+    check!(".421",         [internal_fix!(Nanosecond3NoDot)]; INVALID);
+
+    check!("",             [internal_fix!(Nanosecond6NoDot)]; TOO_SHORT);
+    check!("0",            [internal_fix!(Nanosecond6NoDot)]; TOO_SHORT);
+    check!("42195",        [internal_fix!(Nanosecond6NoDot)]; TOO_SHORT);
+    check!("421950",       [internal_fix!(Nanosecond6NoDot)]; nanosecond: 421_950_000);
+    check!("000003",       [internal_fix!(Nanosecond6NoDot)]; nanosecond: 3000);
+    check!("000000",       [internal_fix!(Nanosecond6NoDot)]; nanosecond: 0);
+    check!("4x",           [internal_fix!(Nanosecond6NoDot)]; TOO_SHORT);
+    check!("     4",       [internal_fix!(Nanosecond6NoDot)]; INVALID);
+    check!(".42100",       [internal_fix!(Nanosecond6NoDot)]; INVALID);
+
+    check!("",             [internal_fix!(Nanosecond9NoDot)]; TOO_SHORT);
+    check!("42195",        [internal_fix!(Nanosecond9NoDot)]; TOO_SHORT);
+    check!("421950803",    [internal_fix!(Nanosecond9NoDot)]; nanosecond: 421_950_803);
+    check!("000000003",    [internal_fix!(Nanosecond9NoDot)]; nanosecond: 3);
+    check!("42195080354",  [internal_fix!(Nanosecond9NoDot), num!(Second)]; nanosecond: 421_950_803, second: 54); // don't skip digits that come after the 9
+    check!("421950803547", [internal_fix!(Nanosecond9NoDot)]; TOO_LONG);
+    check!("000000000",    [internal_fix!(Nanosecond9NoDot)]; nanosecond: 0);
+    check!("00000000x",    [internal_fix!(Nanosecond9NoDot)]; INVALID);
+    check!("        4",    [internal_fix!(Nanosecond9NoDot)]; INVALID);
+    check!(".42100000",    [internal_fix!(Nanosecond9NoDot)]; INVALID);
+
+    // fixed: timezone offsets
+    check!("+00:00",    [fix!(TimezoneOffset)]; offset: 0);
+    check!("-00:00",    [fix!(TimezoneOffset)]; offset: 0);
+    check!("+00:01",    [fix!(TimezoneOffset)]; offset: 60);
+    check!("-00:01",    [fix!(TimezoneOffset)]; offset: -60);
+    check!("+00:30",    [fix!(TimezoneOffset)]; offset: 30 * 60);
+    check!("-00:30",    [fix!(TimezoneOffset)]; offset: -30 * 60);
+    check!("+04:56",    [fix!(TimezoneOffset)]; offset: 296 * 60);
+    check!("-04:56",    [fix!(TimezoneOffset)]; offset: -296 * 60);
+    check!("+24:00",    [fix!(TimezoneOffset)]; offset: 24 * 60 * 60);
+    check!("-24:00",    [fix!(TimezoneOffset)]; offset: -24 * 60 * 60);
+    check!("+99:59",    [fix!(TimezoneOffset)]; offset: (100 * 60 - 1) * 60);
+    check!("-99:59",    [fix!(TimezoneOffset)]; offset: -(100 * 60 - 1) * 60);
+    check!("+00:59",    [fix!(TimezoneOffset)]; offset: 59 * 60);
+    check!("+00:60",    [fix!(TimezoneOffset)]; OUT_OF_RANGE);
+    check!("+00:99",    [fix!(TimezoneOffset)]; OUT_OF_RANGE);
+    check!("#12:34",    [fix!(TimezoneOffset)]; INVALID);
+    check!("12:34",     [fix!(TimezoneOffset)]; INVALID);
+    check!("+12:34 ",   [fix!(TimezoneOffset)]; TOO_LONG);
+    check!(" +12:34",   [fix!(TimezoneOffset)]; offset: 754 * 60);
+    check!("\t -12:34", [fix!(TimezoneOffset)]; offset: -754 * 60);
+    check!("",          [fix!(TimezoneOffset)]; TOO_SHORT);
+    check!("+",         [fix!(TimezoneOffset)]; TOO_SHORT);
+    check!("+1",        [fix!(TimezoneOffset)]; TOO_SHORT);
+    check!("+12",       [fix!(TimezoneOffset)]; TOO_SHORT);
+    check!("+123",      [fix!(TimezoneOffset)]; TOO_SHORT);
+    check!("+1234",     [fix!(TimezoneOffset)]; offset: 754 * 60);
+    check!("+12345",    [fix!(TimezoneOffset)]; TOO_LONG);
+    check!("+12345",    [fix!(TimezoneOffset), num!(Day)]; offset: 754 * 60, day: 5);
+    check!("Z",         [fix!(TimezoneOffset)]; INVALID);
+    check!("z",         [fix!(TimezoneOffset)]; INVALID);
+    check!("Z",         [fix!(TimezoneOffsetZ)]; offset: 0);
+    check!("z",         [fix!(TimezoneOffsetZ)]; offset: 0);
+    check!("Y",         [fix!(TimezoneOffsetZ)]; INVALID);
+    check!("Zulu",      [fix!(TimezoneOffsetZ), lit!("ulu")]; offset: 0);
+    check!("zulu",      [fix!(TimezoneOffsetZ), lit!("ulu")]; offset: 0);
+    check!("+1234ulu",  [fix!(TimezoneOffsetZ), lit!("ulu")]; offset: 754 * 60);
+    check!("+12:34ulu", [fix!(TimezoneOffsetZ), lit!("ulu")]; offset: 754 * 60);
+    check!("Z",         [internal_fix!(TimezoneOffsetPermissive)]; offset: 0);
+    check!("z",         [internal_fix!(TimezoneOffsetPermissive)]; offset: 0);
+    check!("+12:00",    [internal_fix!(TimezoneOffsetPermissive)]; offset: 12 * 60 * 60);
+    check!("+12",       [internal_fix!(TimezoneOffsetPermissive)]; offset: 12 * 60 * 60);
+    check!("CEST 5",    [fix!(TimezoneName), lit!(" "), num!(Day)]; day: 5);
+
+    // some practical examples
+    check!("2015-02-04T14:37:05+09:00",
+           [num!(Year), lit!("-"), num!(Month), lit!("-"), num!(Day), lit!("T"),
+            num!(Hour), lit!(":"), num!(Minute), lit!(":"), num!(Second), fix!(TimezoneOffset)];
+           year: 2015, month: 2, day: 4, hour_div_12: 1, hour_mod_12: 2,
+           minute: 37, second: 5, offset: 32400);
+    check!("20150204143705567",
+            [num!(Year), num!(Month), num!(Day),
+            num!(Hour), num!(Minute), num!(Second), internal_fix!(Nanosecond3NoDot)];
+            year: 2015, month: 2, day: 4, hour_div_12: 1, hour_mod_12: 2,
+            minute: 37, second: 5, nanosecond: 567000000);
+    check!("Mon, 10 Jun 2013 09:32:37 GMT",
+           [fix!(ShortWeekdayName), lit!(","), sp!(" "), num!(Day), sp!(" "),
+            fix!(ShortMonthName), sp!(" "), num!(Year), sp!(" "), num!(Hour), lit!(":"),
+            num!(Minute), lit!(":"), num!(Second), sp!(" "), lit!("GMT")];
+           year: 2013, month: 6, day: 10, weekday: Weekday::Mon,
+           hour_div_12: 0, hour_mod_12: 9, minute: 32, second: 37);
+    check!("Sun Aug 02 13:39:15 CEST 2020",
+            [fix!(ShortWeekdayName), sp!(" "), fix!(ShortMonthName), sp!(" "),
+            num!(Day), sp!(" "), num!(Hour), lit!(":"), num!(Minute), lit!(":"),
+            num!(Second), sp!(" "), fix!(TimezoneName), sp!(" "), num!(Year)];
+            year: 2020, month: 8, day: 2, weekday: Weekday::Sun,
+            hour_div_12: 1, hour_mod_12: 1, minute: 39, second: 15);
+    check!("20060102150405",
+           [num!(Year), num!(Month), num!(Day), num!(Hour), num!(Minute), num!(Second)];
+           year: 2006, month: 1, day: 2, hour_div_12: 1, hour_mod_12: 3, minute: 4, second: 5);
+    check!("3:14PM",
+           [num!(Hour12), lit!(":"), num!(Minute), fix!(LowerAmPm)];
+           hour_div_12: 1, hour_mod_12: 3, minute: 14);
+    check!("12345678901234.56789",
+           [num!(Timestamp), lit!("."), num!(Nanosecond)];
+           nanosecond: 56_789, timestamp: 12_345_678_901_234);
+    check!("12345678901234.56789",
+           [num!(Timestamp), fix!(Nanosecond)];
+           nanosecond: 567_890_000, timestamp: 12_345_678_901_234);
+}
+
+#[cfg(test)]
+#[test]
+fn test_rfc2822() {
+    use super::NOT_ENOUGH;
+    use super::*;
+    use crate::offset::FixedOffset;
+    use crate::DateTime;
+
+    // Test data - (input, Ok(expected result after parse and format) or Err(error code))
+    let testdates = [
+        ("Tue, 20 Jan 2015 17:35:20 -0800", Ok("Tue, 20 Jan 2015 17:35:20 -0800")), // normal case
+        ("Fri,  2 Jan 2015 17:35:20 -0800", Ok("Fri, 02 Jan 2015 17:35:20 -0800")), // folding whitespace
+        ("Fri, 02 Jan 2015 17:35:20 -0800", Ok("Fri, 02 Jan 2015 17:35:20 -0800")), // leading zero
+        ("Tue, 20 Jan 2015 17:35:20 -0800 (UTC)", Ok("Tue, 20 Jan 2015 17:35:20 -0800")), // trailing comment
+        (
+            r"Tue, 20 Jan 2015 17:35:20 -0800 ( (UTC ) (\( (a)\(( \t ) ) \\( \) ))",
+            Ok("Tue, 20 Jan 2015 17:35:20 -0800"),
+        ), // complex trailing comment
+        (r"Tue, 20 Jan 2015 17:35:20 -0800 (UTC\)", Err(TOO_LONG)), // incorrect comment, not enough closing parentheses
+        (
+            "Tue, 20 Jan 2015 17:35:20 -0800 (UTC)\t \r\n(Anothercomment)",
+            Ok("Tue, 20 Jan 2015 17:35:20 -0800"),
+        ), // multiple comments
+        ("Tue, 20 Jan 2015 17:35:20 -0800 (UTC) ", Err(TOO_LONG)), // trailing whitespace after comment
+        ("20 Jan 2015 17:35:20 -0800", Ok("Tue, 20 Jan 2015 17:35:20 -0800")), // no day of week
+        ("20 JAN 2015 17:35:20 -0800", Ok("Tue, 20 Jan 2015 17:35:20 -0800")), // upper case month
+        ("Tue, 20 Jan 2015 17:35 -0800", Ok("Tue, 20 Jan 2015 17:35:00 -0800")), // no second
+        ("11 Sep 2001 09:45:00 EST", Ok("Tue, 11 Sep 2001 09:45:00 -0500")),
+        ("30 Feb 2015 17:35:20 -0800", Err(OUT_OF_RANGE)), // bad day of month
+        ("Tue, 20 Jan 2015", Err(TOO_SHORT)),              // omitted fields
+        ("Tue, 20 Avr 2015 17:35:20 -0800", Err(INVALID)), // bad month name
+        ("Tue, 20 Jan 2015 25:35:20 -0800", Err(OUT_OF_RANGE)), // bad hour
+        ("Tue, 20 Jan 2015 7:35:20 -0800", Err(INVALID)),  // bad # of digits in hour
+        ("Tue, 20 Jan 2015 17:65:20 -0800", Err(OUT_OF_RANGE)), // bad minute
+        ("Tue, 20 Jan 2015 17:35:90 -0800", Err(OUT_OF_RANGE)), // bad second
+        ("Tue, 20 Jan 2015 17:35:20 -0890", Err(OUT_OF_RANGE)), // bad offset
+        ("6 Jun 1944 04:00:00Z", Err(INVALID)),            // bad offset (zulu not allowed)
+        ("Tue, 20 Jan 2015 17:35:20 HAS", Err(NOT_ENOUGH)), // bad named time zone
+    ];
+
+    fn rfc2822_to_datetime(date: &str) -> ParseResult<DateTime<FixedOffset>> {
+        let mut parsed = Parsed::new();
+        parse(&mut parsed, date, [Item::Fixed(Fixed::RFC2822)].iter())?;
+        parsed.to_datetime()
+    }
+
+    fn fmt_rfc2822_datetime(dt: DateTime<FixedOffset>) -> String {
+        dt.format_with_items([Item::Fixed(Fixed::RFC2822)].iter()).to_string()
+    }
+
+    // Test against test data above
+    for &(date, checkdate) in testdates.iter() {
+        let d = rfc2822_to_datetime(date); // parse a date
+        let dt = match d {
+            // did we get a value?
+            Ok(dt) => Ok(fmt_rfc2822_datetime(dt)), // yes, go on
+            Err(e) => Err(e),                       // otherwise keep an error for the comparison
+        };
+        if dt != checkdate.map(|s| s.to_string()) {
+            // check for expected result
+            panic!(
+                "Date conversion failed for {}\nReceived: {:?}\nExpected: {:?}",
+                date, dt, checkdate
+            );
+        }
+    }
+}
+
+#[cfg(test)]
+#[test]
+fn parse_rfc850() {
+    use crate::{TimeZone, Utc};
+
+    static RFC850_FMT: &str = "%A, %d-%b-%y %T GMT";
+
+    let dt_str = "Sunday, 06-Nov-94 08:49:37 GMT";
+    let dt = Utc.with_ymd_and_hms(1994, 11, 6, 8, 49, 37).unwrap();
+
+    // Check that the format is what we expect
+    assert_eq!(dt.format(RFC850_FMT).to_string(), dt_str);
+
+    // Check that it parses correctly
+    assert_eq!(Ok(dt), Utc.datetime_from_str("Sunday, 06-Nov-94 08:49:37 GMT", RFC850_FMT));
+
+    // Check that the rest of the weekdays parse correctly (this test originally failed because
+    // Sunday parsed incorrectly).
+    let testdates = [
+        (Utc.with_ymd_and_hms(1994, 11, 7, 8, 49, 37).unwrap(), "Monday, 07-Nov-94 08:49:37 GMT"),
+        (Utc.with_ymd_and_hms(1994, 11, 8, 8, 49, 37).unwrap(), "Tuesday, 08-Nov-94 08:49:37 GMT"),
+        (
+            Utc.with_ymd_and_hms(1994, 11, 9, 8, 49, 37).unwrap(),
+            "Wednesday, 09-Nov-94 08:49:37 GMT",
+        ),
+        (
+            Utc.with_ymd_and_hms(1994, 11, 10, 8, 49, 37).unwrap(),
+            "Thursday, 10-Nov-94 08:49:37 GMT",
+        ),
+        (Utc.with_ymd_and_hms(1994, 11, 11, 8, 49, 37).unwrap(), "Friday, 11-Nov-94 08:49:37 GMT"),
+        (
+            Utc.with_ymd_and_hms(1994, 11, 12, 8, 49, 37).unwrap(),
+            "Saturday, 12-Nov-94 08:49:37 GMT",
+        ),
+    ];
+
+    for val in &testdates {
+        assert_eq!(Ok(val.0), Utc.datetime_from_str(val.1, RFC850_FMT));
+    }
+}
+
+#[cfg(test)]
+#[test]
+fn test_rfc3339() {
+    use super::*;
+    use crate::offset::FixedOffset;
+    use crate::DateTime;
+
+    // Test data - (input, Ok(expected result after parse and format) or Err(error code))
+    let testdates = [
+        ("2015-01-20T17:35:20-08:00", Ok("2015-01-20T17:35:20-08:00")), // normal case
+        ("1944-06-06T04:04:00Z", Ok("1944-06-06T04:04:00+00:00")),      // D-day
+        ("2001-09-11T09:45:00-08:00", Ok("2001-09-11T09:45:00-08:00")),
+        ("2015-01-20T17:35:20.001-08:00", Ok("2015-01-20T17:35:20.001-08:00")),
+        ("2015-01-20T17:35:20.000031-08:00", Ok("2015-01-20T17:35:20.000031-08:00")),
+        ("2015-01-20T17:35:20.000000004-08:00", Ok("2015-01-20T17:35:20.000000004-08:00")),
+        ("2015-01-20T17:35:20.000000000452-08:00", Ok("2015-01-20T17:35:20-08:00")), // too small
+        ("2015-02-30T17:35:20-08:00", Err(OUT_OF_RANGE)), // bad day of month
+        ("2015-01-20T25:35:20-08:00", Err(OUT_OF_RANGE)), // bad hour
+        ("2015-01-20T17:65:20-08:00", Err(OUT_OF_RANGE)), // bad minute
+        ("2015-01-20T17:35:90-08:00", Err(OUT_OF_RANGE)), // bad second
+        ("2015-01-20T17:35:20-24:00", Err(OUT_OF_RANGE)), // bad offset
+    ];
+
+    fn rfc3339_to_datetime(date: &str) -> ParseResult<DateTime<FixedOffset>> {
+        let mut parsed = Parsed::new();
+        parse(&mut parsed, date, [Item::Fixed(Fixed::RFC3339)].iter())?;
+        parsed.to_datetime()
+    }
+
+    fn fmt_rfc3339_datetime(dt: DateTime<FixedOffset>) -> String {
+        dt.format_with_items([Item::Fixed(Fixed::RFC3339)].iter()).to_string()
+    }
+
+    // Test against test data above
+    for &(date, checkdate) in testdates.iter() {
+        let d = rfc3339_to_datetime(date); // parse a date
+        let dt = match d {
+            // did we get a value?
+            Ok(dt) => Ok(fmt_rfc3339_datetime(dt)), // yes, go on
+            Err(e) => Err(e),                       // otherwise keep an error for the comparison
+        };
+        if dt != checkdate.map(|s| s.to_string()) {
+            // check for expected result
+            panic!(
+                "Date conversion failed for {}\nReceived: {:?}\nExpected: {:?}",
+                date, dt, checkdate
+            );
+        }
+    }
+}

javascript-engine/external/chrono/src/format/scan.rs

@@ -0,0 +1,415 @@
+// This is a part of Chrono.
+// See README.md and LICENSE.txt for details.
+
+/*!
+ * Various scanning routines for the parser.
+ */
+
+#![allow(deprecated)]
+
+use super::{ParseResult, INVALID, OUT_OF_RANGE, TOO_SHORT};
+use crate::Weekday;
+
+/// Returns true when two slices are equal case-insensitively (in ASCII).
+/// Assumes that the `pattern` is already converted to lower case.
+fn equals(s: &str, pattern: &str) -> bool {
+    let mut xs = s.as_bytes().iter().map(|&c| match c {
+        b'A'..=b'Z' => c + 32,
+        _ => c,
+    });
+    let mut ys = pattern.as_bytes().iter().cloned();
+    loop {
+        match (xs.next(), ys.next()) {
+            (None, None) => return true,
+            (None, _) | (_, None) => return false,
+            (Some(x), Some(y)) if x != y => return false,
+            _ => (),
+        }
+    }
+}
+
+/// Tries to parse the non-negative number from `min` to `max` digits.
+///
+/// The absence of digits at all is an unconditional error.
+/// More than `max` digits are consumed up to the first `max` digits.
+/// Any number that does not fit in `i64` is an error.
+#[inline]
+pub(super) fn number(s: &str, min: usize, max: usize) -> ParseResult<(&str, i64)> {
+    assert!(min <= max);
+
+    // We are only interested in ascii numbers, so we can work with the `str` as bytes. We stop on
+    // the first non-numeric byte, which may be another ascii character or beginning of multi-byte
+    // UTF-8 character.
+    let bytes = s.as_bytes();
+    if bytes.len() < min {
+        return Err(TOO_SHORT);
+    }
+
+    let mut n = 0i64;
+    for (i, c) in bytes.iter().take(max).cloned().enumerate() {
+        // cloned() = copied()
+        if !(b'0'..=b'9').contains(&c) {
+            if i < min {
+                return Err(INVALID);
+            } else {
+                return Ok((&s[i..], n));
+            }
+        }
+
+        n = match n.checked_mul(10).and_then(|n| n.checked_add((c - b'0') as i64)) {
+            Some(n) => n,
+            None => return Err(OUT_OF_RANGE),
+        };
+    }
+
+    Ok((&s[core::cmp::min(max, bytes.len())..], n))
+}
+
+/// Tries to consume at least one digits as a fractional second.
+/// Returns the number of whole nanoseconds (0--999,999,999).
+pub(super) fn nanosecond(s: &str) -> ParseResult<(&str, i64)> {
+    // record the number of digits consumed for later scaling.
+    let origlen = s.len();
+    let (s, v) = number(s, 1, 9)?;
+    let consumed = origlen - s.len();
+
+    // scale the number accordingly.
+    static SCALE: [i64; 10] =
+        [0, 100_000_000, 10_000_000, 1_000_000, 100_000, 10_000, 1_000, 100, 10, 1];
+    let v = v.checked_mul(SCALE[consumed]).ok_or(OUT_OF_RANGE)?;
+
+    // if there are more than 9 digits, skip next digits.
+    let s = s.trim_left_matches(|c: char| ('0'..='9').contains(&c));
+
+    Ok((s, v))
+}
+
+/// Tries to consume a fixed number of digits as a fractional second.
+/// Returns the number of whole nanoseconds (0--999,999,999).
+pub(super) fn nanosecond_fixed(s: &str, digits: usize) -> ParseResult<(&str, i64)> {
+    // record the number of digits consumed for later scaling.
+    let (s, v) = number(s, digits, digits)?;
+
+    // scale the number accordingly.
+    static SCALE: [i64; 10] =
+        [0, 100_000_000, 10_000_000, 1_000_000, 100_000, 10_000, 1_000, 100, 10, 1];
+    let v = v.checked_mul(SCALE[digits]).ok_or(OUT_OF_RANGE)?;
+
+    Ok((s, v))
+}
+
+/// Tries to parse the month index (0 through 11) with the first three ASCII letters.
+pub(super) fn short_month0(s: &str) -> ParseResult<(&str, u8)> {
+    if s.len() < 3 {
+        return Err(TOO_SHORT);
+    }
+    let buf = s.as_bytes();
+    let month0 = match (buf[0] | 32, buf[1] | 32, buf[2] | 32) {
+        (b'j', b'a', b'n') => 0,
+        (b'f', b'e', b'b') => 1,
+        (b'm', b'a', b'r') => 2,
+        (b'a', b'p', b'r') => 3,
+        (b'm', b'a', b'y') => 4,
+        (b'j', b'u', b'n') => 5,
+        (b'j', b'u', b'l') => 6,
+        (b'a', b'u', b'g') => 7,
+        (b's', b'e', b'p') => 8,
+        (b'o', b'c', b't') => 9,
+        (b'n', b'o', b'v') => 10,
+        (b'd', b'e', b'c') => 11,
+        _ => return Err(INVALID),
+    };
+    Ok((&s[3..], month0))
+}
+
+/// Tries to parse the weekday with the first three ASCII letters.
+pub(super) fn short_weekday(s: &str) -> ParseResult<(&str, Weekday)> {
+    if s.len() < 3 {
+        return Err(TOO_SHORT);
+    }
+    let buf = s.as_bytes();
+    let weekday = match (buf[0] | 32, buf[1] | 32, buf[2] | 32) {
+        (b'm', b'o', b'n') => Weekday::Mon,
+        (b't', b'u', b'e') => Weekday::Tue,
+        (b'w', b'e', b'd') => Weekday::Wed,
+        (b't', b'h', b'u') => Weekday::Thu,
+        (b'f', b'r', b'i') => Weekday::Fri,
+        (b's', b'a', b't') => Weekday::Sat,
+        (b's', b'u', b'n') => Weekday::Sun,
+        _ => return Err(INVALID),
+    };
+    Ok((&s[3..], weekday))
+}
+
+/// Tries to parse the month index (0 through 11) with short or long month names.
+/// It prefers long month names to short month names when both are possible.
+pub(super) fn short_or_long_month0(s: &str) -> ParseResult<(&str, u8)> {
+    // lowercased month names, minus first three chars
+    static LONG_MONTH_SUFFIXES: [&str; 12] =
+        ["uary", "ruary", "ch", "il", "", "e", "y", "ust", "tember", "ober", "ember", "ember"];
+
+    let (mut s, month0) = short_month0(s)?;
+
+    // tries to consume the suffix if possible
+    let suffix = LONG_MONTH_SUFFIXES[month0 as usize];
+    if s.len() >= suffix.len() && equals(&s[..suffix.len()], suffix) {
+        s = &s[suffix.len()..];
+    }
+
+    Ok((s, month0))
+}
+
+/// Tries to parse the weekday with short or long weekday names.
+/// It prefers long weekday names to short weekday names when both are possible.
+pub(super) fn short_or_long_weekday(s: &str) -> ParseResult<(&str, Weekday)> {
+    // lowercased weekday names, minus first three chars
+    static LONG_WEEKDAY_SUFFIXES: [&str; 7] =
+        ["day", "sday", "nesday", "rsday", "day", "urday", "day"];
+
+    let (mut s, weekday) = short_weekday(s)?;
+
+    // tries to consume the suffix if possible
+    let suffix = LONG_WEEKDAY_SUFFIXES[weekday.num_days_from_monday() as usize];
+    if s.len() >= suffix.len() && equals(&s[..suffix.len()], suffix) {
+        s = &s[suffix.len()..];
+    }
+
+    Ok((s, weekday))
+}
+
+/// Tries to consume exactly one given character.
+pub(super) fn char(s: &str, c1: u8) -> ParseResult<&str> {
+    match s.as_bytes().first() {
+        Some(&c) if c == c1 => Ok(&s[1..]),
+        Some(_) => Err(INVALID),
+        None => Err(TOO_SHORT),
+    }
+}
+
+/// Tries to consume one or more whitespace.
+pub(super) fn space(s: &str) -> ParseResult<&str> {
+    let s_ = s.trim_left();
+    if s_.len() < s.len() {
+        Ok(s_)
+    } else if s.is_empty() {
+        Err(TOO_SHORT)
+    } else {
+        Err(INVALID)
+    }
+}
+
+/// Consumes any number (including zero) of colon or spaces.
+pub(super) fn colon_or_space(s: &str) -> ParseResult<&str> {
+    Ok(s.trim_left_matches(|c: char| c == ':' || c.is_whitespace()))
+}
+
+/// Tries to parse `[-+]\d\d` continued by `\d\d`. Return an offset in seconds if possible.
+///
+/// The additional `colon` may be used to parse a mandatory or optional `:`
+/// between hours and minutes, and should return either a new suffix or `Err` when parsing fails.
+pub(super) fn timezone_offset<F>(s: &str, consume_colon: F) -> ParseResult<(&str, i32)>
+where
+    F: FnMut(&str) -> ParseResult<&str>,
+{
+    timezone_offset_internal(s, consume_colon, false)
+}
+
+fn timezone_offset_internal<F>(
+    mut s: &str,
+    mut consume_colon: F,
+    allow_missing_minutes: bool,
+) -> ParseResult<(&str, i32)>
+where
+    F: FnMut(&str) -> ParseResult<&str>,
+{
+    fn digits(s: &str) -> ParseResult<(u8, u8)> {
+        let b = s.as_bytes();
+        if b.len() < 2 {
+            Err(TOO_SHORT)
+        } else {
+            Ok((b[0], b[1]))
+        }
+    }
+    let negative = match s.as_bytes().first() {
+        Some(&b'+') => false,
+        Some(&b'-') => true,
+        Some(_) => return Err(INVALID),
+        None => return Err(TOO_SHORT),
+    };
+    s = &s[1..];
+
+    // hours (00--99)
+    let hours = match digits(s)? {
+        (h1 @ b'0'..=b'9', h2 @ b'0'..=b'9') => i32::from((h1 - b'0') * 10 + (h2 - b'0')),
+        _ => return Err(INVALID),
+    };
+    s = &s[2..];
+
+    // colons (and possibly other separators)
+    s = consume_colon(s)?;
+
+    // minutes (00--59)
+    // if the next two items are digits then we have to add minutes
+    let minutes = if let Ok(ds) = digits(s) {
+        match ds {
+            (m1 @ b'0'..=b'5', m2 @ b'0'..=b'9') => i32::from((m1 - b'0') * 10 + (m2 - b'0')),
+            (b'6'..=b'9', b'0'..=b'9') => return Err(OUT_OF_RANGE),
+            _ => return Err(INVALID),
+        }
+    } else if allow_missing_minutes {
+        0
+    } else {
+        return Err(TOO_SHORT);
+    };
+    s = match s.len() {
+        len if len >= 2 => &s[2..],
+        len if len == 0 => s,
+        _ => return Err(TOO_SHORT),
+    };
+
+    let seconds = hours * 3600 + minutes * 60;
+    Ok((s, if negative { -seconds } else { seconds }))
+}
+
+/// Same as `timezone_offset` but also allows for `z`/`Z` which is the same as `+00:00`.
+pub(super) fn timezone_offset_zulu<F>(s: &str, colon: F) -> ParseResult<(&str, i32)>
+where
+    F: FnMut(&str) -> ParseResult<&str>,
+{
+    let bytes = s.as_bytes();
+    match bytes.first() {
+        Some(&b'z') | Some(&b'Z') => Ok((&s[1..], 0)),
+        Some(&b'u') | Some(&b'U') => {
+            if bytes.len() >= 3 {
+                let (b, c) = (bytes[1], bytes[2]);
+                match (b | 32, c | 32) {
+                    (b't', b'c') => Ok((&s[3..], 0)),
+                    _ => Err(INVALID),
+                }
+            } else {
+                Err(INVALID)
+            }
+        }
+        _ => timezone_offset(s, colon),
+    }
+}
+
+/// Same as `timezone_offset` but also allows for `z`/`Z` which is the same as
+/// `+00:00`, and allows missing minutes entirely.
+pub(super) fn timezone_offset_permissive<F>(s: &str, colon: F) -> ParseResult<(&str, i32)>
+where
+    F: FnMut(&str) -> ParseResult<&str>,
+{
+    match s.as_bytes().first() {
+        Some(&b'z') | Some(&b'Z') => Ok((&s[1..], 0)),
+        _ => timezone_offset_internal(s, colon, true),
+    }
+}
+
+/// Same as `timezone_offset` but also allows for RFC 2822 legacy timezones.
+/// May return `None` which indicates an insufficient offset data (i.e. `-0000`).
+pub(super) fn timezone_offset_2822(s: &str) -> ParseResult<(&str, Option<i32>)> {
+    // tries to parse legacy time zone names
+    let upto = s
+        .as_bytes()
+        .iter()
+        .position(|&c| match c {
+            b'a'..=b'z' | b'A'..=b'Z' => false,
+            _ => true,
+        })
+        .unwrap_or(s.len());
+    if upto > 0 {
+        let name = &s[..upto];
+        let s = &s[upto..];
+        let offset_hours = |o| Ok((s, Some(o * 3600)));
+        if equals(name, "gmt") || equals(name, "ut") {
+            offset_hours(0)
+        } else if equals(name, "edt") {
+            offset_hours(-4)
+        } else if equals(name, "est") || equals(name, "cdt") {
+            offset_hours(-5)
+        } else if equals(name, "cst") || equals(name, "mdt") {
+            offset_hours(-6)
+        } else if equals(name, "mst") || equals(name, "pdt") {
+            offset_hours(-7)
+        } else if equals(name, "pst") {
+            offset_hours(-8)
+        } else {
+            Ok((s, None)) // recommended by RFC 2822: consume but treat it as -0000
+        }
+    } else {
+        let (s_, offset) = timezone_offset(s, |s| Ok(s))?;
+        Ok((s_, Some(offset)))
+    }
+}
+
+/// Tries to consume everything until next whitespace-like symbol.
+/// Does not provide any offset information from the consumed data.
+pub(super) fn timezone_name_skip(s: &str) -> ParseResult<(&str, ())> {
+    Ok((s.trim_left_matches(|c: char| !c.is_whitespace()), ()))
+}
+
+/// Tries to consume an RFC2822 comment including preceding ` `.
+///
+/// Returns the remaining string after the closing parenthesis.
+pub(super) fn comment_2822(s: &str) -> ParseResult<(&str, ())> {
+    use CommentState::*;
+
+    let s = s.trim_start();
+
+    let mut state = Start;
+    for (i, c) in s.bytes().enumerate() {
+        state = match (state, c) {
+            (Start, b'(') => Next(1),
+            (Next(1), b')') => return Ok((&s[i + 1..], ())),
+            (Next(depth), b'\\') => Escape(depth),
+            (Next(depth), b'(') => Next(depth + 1),
+            (Next(depth), b')') => Next(depth - 1),
+            (Next(depth), _) | (Escape(depth), _) => Next(depth),
+            _ => return Err(INVALID),
+        };
+    }
+
+    Err(TOO_SHORT)
+}
+
+enum CommentState {
+    Start,
+    Next(usize),
+    Escape(usize),
+}
+
+#[cfg(test)]
+#[test]
+fn test_rfc2822_comments() {
+    let testdata = [
+        ("", Err(TOO_SHORT)),
+        (" ", Err(TOO_SHORT)),
+        ("x", Err(INVALID)),
+        ("(", Err(TOO_SHORT)),
+        ("()", Ok("")),
+        (" \r\n\t()", Ok("")),
+        ("() ", Ok(" ")),
+        ("()z", Ok("z")),
+        ("(x)", Ok("")),
+        ("(())", Ok("")),
+        ("((()))", Ok("")),
+        ("(x(x(x)x)x)", Ok("")),
+        ("( x ( x ( x ) x ) x )", Ok("")),
+        (r"(\)", Err(TOO_SHORT)),
+        (r"(\()", Ok("")),
+        (r"(\))", Ok("")),
+        (r"(\\)", Ok("")),
+        ("(()())", Ok("")),
+        ("( x ( x ) x ( x ) x )", Ok("")),
+    ];
+
+    for (test_in, expected) in testdata.iter() {
+        let actual = comment_2822(test_in).map(|(s, _)| s);
+        assert_eq!(
+            *expected, actual,
+            "{:?} expected to produce {:?}, but produced {:?}.",
+            test_in, expected, actual
+        );
+    }
+}

javascript-engine/external/chrono/src/format/strftime.rs

@@ -0,0 +1,712 @@
+// This is a part of Chrono.
+// See README.md and LICENSE.txt for details.
+
+/*!
+`strftime`/`strptime`-inspired date and time formatting syntax.
+
+## Specifiers
+
+The following specifiers are available both to formatting and parsing.
+
+| Spec. | Example  | Description                                                                |
+|-------|----------|----------------------------------------------------------------------------|
+|       |          | **DATE SPECIFIERS:**                                                       |
+| `%Y`  | `2001`   | The full proleptic Gregorian year, zero-padded to 4 digits. chrono supports years from -262144 to 262143. |
+| `%C`  | `20`     | The proleptic Gregorian year divided by 100, zero-padded to 2 digits. [^1] |
+| `%y`  | `01`     | The proleptic Gregorian year modulo 100, zero-padded to 2 digits. [^1]     |
+|       |          |                                                                            |
+| `%m`  | `07`     | Month number (01--12), zero-padded to 2 digits.                            |
+| `%b`  | `Jul`    | Abbreviated month name. Always 3 letters.                                  |
+| `%B`  | `July`   | Full month name. Also accepts corresponding abbreviation in parsing.       |
+| `%h`  | `Jul`    | Same as `%b`.                                                              |
+|       |          |                                                                            |
+| `%d`  | `08`     | Day number (01--31), zero-padded to 2 digits.                              |
+| `%e`  | ` 8`     | Same as `%d` but space-padded. Same as `%_d`.                              |
+|       |          |                                                                            |
+| `%a`  | `Sun`    | Abbreviated weekday name. Always 3 letters.                                |
+| `%A`  | `Sunday` | Full weekday name. Also accepts corresponding abbreviation in parsing.     |
+| `%w`  | `0`      | Sunday = 0, Monday = 1, ..., Saturday = 6.                                 |
+| `%u`  | `7`      | Monday = 1, Tuesday = 2, ..., Sunday = 7. (ISO 8601)                       |
+|       |          |                                                                            |
+| `%U`  | `28`     | Week number starting with Sunday (00--53), zero-padded to 2 digits. [^2]   |
+| `%W`  | `27`     | Same as `%U`, but week 1 starts with the first Monday in that year instead.|
+|       |          |                                                                            |
+| `%G`  | `2001`   | Same as `%Y` but uses the year number in ISO 8601 week date. [^3]          |
+| `%g`  | `01`     | Same as `%y` but uses the year number in ISO 8601 week date. [^3]          |
+| `%V`  | `27`     | Same as `%U` but uses the week number in ISO 8601 week date (01--53). [^3] |
+|       |          |                                                                            |
+| `%j`  | `189`    | Day of the year (001--366), zero-padded to 3 digits.                       |
+|       |          |                                                                            |
+| `%D`  | `07/08/01`    | Month-day-year format. Same as `%m/%d/%y`.                            |
+| `%x`  | `07/08/01`    | Locale's date representation (e.g., 12/31/99).                        |
+| `%F`  | `2001-07-08`  | Year-month-day format (ISO 8601). Same as `%Y-%m-%d`.                 |
+| `%v`  | ` 8-Jul-2001` | Day-month-year format. Same as `%e-%b-%Y`.                            |
+|       |          |                                                                            |
+|       |          | **TIME SPECIFIERS:**                                                       |
+| `%H`  | `00`     | Hour number (00--23), zero-padded to 2 digits.                             |
+| `%k`  | ` 0`     | Same as `%H` but space-padded. Same as `%_H`.                              |
+| `%I`  | `12`     | Hour number in 12-hour clocks (01--12), zero-padded to 2 digits.           |
+| `%l`  | `12`     | Same as `%I` but space-padded. Same as `%_I`.                              |
+|       |          |                                                                            |
+| `%P`  | `am`     | `am` or `pm` in 12-hour clocks.                                            |
+| `%p`  | `AM`     | `AM` or `PM` in 12-hour clocks.                                            |
+|       |          |                                                                            |
+| `%M`  | `34`     | Minute number (00--59), zero-padded to 2 digits.                           |
+| `%S`  | `60`     | Second number (00--60), zero-padded to 2 digits. [^4]                      |
+| `%f`  | `026490000`   | The fractional seconds (in nanoseconds) since last whole second. [^7] |
+| `%.f` | `.026490`| Similar to `.%f` but left-aligned. These all consume the leading dot. [^7] |
+| `%.3f`| `.026`        | Similar to `.%f` but left-aligned but fixed to a length of 3. [^7]    |
+| `%.6f`| `.026490`     | Similar to `.%f` but left-aligned but fixed to a length of 6. [^7]    |
+| `%.9f`| `.026490000`  | Similar to `.%f` but left-aligned but fixed to a length of 9. [^7]    |
+| `%3f` | `026`         | Similar to `%.3f` but without the leading dot. [^7]                   |
+| `%6f` | `026490`      | Similar to `%.6f` but without the leading dot. [^7]                   |
+| `%9f` | `026490000`   | Similar to `%.9f` but without the leading dot. [^7]                   |
+|       |               |                                                                       |
+| `%R`  | `00:34`       | Hour-minute format. Same as `%H:%M`.                                  |
+| `%T`  | `00:34:60`    | Hour-minute-second format. Same as `%H:%M:%S`.                        |
+| `%X`  | `00:34:60`    | Locale's time representation (e.g., 23:13:48).                        |
+| `%r`  | `12:34:60 AM` | Hour-minute-second format in 12-hour clocks. Same as `%I:%M:%S %p`.   |
+|       |          |                                                                            |
+|       |          | **TIME ZONE SPECIFIERS:**                                                  |
+| `%Z`  | `ACST`   | Local time zone name. Skips all non-whitespace characters during parsing. [^8] |
+| `%z`  | `+0930`  | Offset from the local time to UTC (with UTC being `+0000`).                |
+| `%:z` | `+09:30` | Same as `%z` but with a colon.                                             |
+|`%::z`|`+09:30:00`| Offset from the local time to UTC with seconds.                            |
+|`%:::z`| `+09`    | Offset from the local time to UTC without minutes.                         |
+| `%#z` | `+09`    | *Parsing only:* Same as `%z` but allows minutes to be missing or present.  |
+|       |          |                                                                            |
+|       |          | **DATE & TIME SPECIFIERS:**                                                |
+|`%c`|`Sun Jul  8 00:34:60 2001`|Locale's date and time (e.g., Thu Mar  3 23:05:25 2005).       |
+| `%+`  | `2001-07-08T00:34:60.026490+09:30` | ISO 8601 / RFC 3339 date & time format. [^5]     |
+|       |               |                                                                       |
+| `%s`  | `994518299`   | UNIX timestamp, the number of seconds since 1970-01-01 00:00 UTC. [^6]|
+|       |          |                                                                            |
+|       |          | **SPECIAL SPECIFIERS:**                                                    |
+| `%t`  |          | Literal tab (`\t`).                                                        |
+| `%n`  |          | Literal newline (`\n`).                                                    |
+| `%%`  |          | Literal percent sign.                                                      |
+
+It is possible to override the default padding behavior of numeric specifiers `%?`.
+This is not allowed for other specifiers and will result in the `BAD_FORMAT` error.
+
+Modifier | Description
+-------- | -----------
+`%-?`    | Suppresses any padding including spaces and zeroes. (e.g. `%j` = `012`, `%-j` = `12`)
+`%_?`    | Uses spaces as a padding. (e.g. `%j` = `012`, `%_j` = ` 12`)
+`%0?`    | Uses zeroes as a padding. (e.g. `%e` = ` 9`, `%0e` = `09`)
+
+Notes:
+
+[^1]: `%C`, `%y`:
+   This is floor division, so 100 BCE (year number -99) will print `-1` and `99` respectively.
+
+[^2]: `%U`:
+   Week 1 starts with the first Sunday in that year.
+   It is possible to have week 0 for days before the first Sunday.
+
+[^3]: `%G`, `%g`, `%V`:
+   Week 1 is the first week with at least 4 days in that year.
+   Week 0 does not exist, so this should be used with `%G` or `%g`.
+
+[^4]: `%S`:
+   It accounts for leap seconds, so `60` is possible.
+
+[^5]: `%+`: Same as `%Y-%m-%dT%H:%M:%S%.f%:z`, i.e. 0, 3, 6 or 9 fractional
+   digits for seconds and colons in the time zone offset.
+   <br>
+   <br>
+   This format also supports having a `Z` or `UTC` in place of `%:z`. They
+   are equivalent to `+00:00`.
+   <br>
+   <br>
+   Note that all `T`, `Z`, and `UTC` are parsed case-insensitively.
+   <br>
+   <br>
+   The typical `strftime` implementations have different (and locale-dependent)
+   formats for this specifier. While Chrono's format for `%+` is far more
+   stable, it is best to avoid this specifier if you want to control the exact
+   output.
+
+[^6]: `%s`:
+   This is not padded and can be negative.
+   For the purpose of Chrono, it only accounts for non-leap seconds
+   so it slightly differs from ISO C `strftime` behavior.
+
+[^7]: `%f`, `%.f`, `%.3f`, `%.6f`, `%.9f`, `%3f`, `%6f`, `%9f`:
+   <br>
+   The default `%f` is right-aligned and always zero-padded to 9 digits
+   for the compatibility with glibc and others,
+   so it always counts the number of nanoseconds since the last whole second.
+   E.g. 7ms after the last second will print `007000000`,
+   and parsing `7000000` will yield the same.
+   <br>
+   <br>
+   The variant `%.f` is left-aligned and print 0, 3, 6 or 9 fractional digits
+   according to the precision.
+   E.g. 70ms after the last second under `%.f` will print `.070` (note: not `.07`),
+   and parsing `.07`, `.070000` etc. will yield the same.
+   Note that they can print or read nothing if the fractional part is zero or
+   the next character is not `.`.
+   <br>
+   <br>
+   The variant `%.3f`, `%.6f` and `%.9f` are left-aligned and print 3, 6 or 9 fractional digits
+   according to the number preceding `f`.
+   E.g. 70ms after the last second under `%.3f` will print `.070` (note: not `.07`),
+   and parsing `.07`, `.070000` etc. will yield the same.
+   Note that they can read nothing if the fractional part is zero or
+   the next character is not `.` however will print with the specified length.
+   <br>
+   <br>
+   The variant `%3f`, `%6f` and `%9f` are left-aligned and print 3, 6 or 9 fractional digits
+   according to the number preceding `f`, but without the leading dot.
+   E.g. 70ms after the last second under `%3f` will print `070` (note: not `07`),
+   and parsing `07`, `070000` etc. will yield the same.
+   Note that they can read nothing if the fractional part is zero.
+
+[^8]: `%Z`:
+   Offset will not be populated from the parsed data, nor will it be validated.
+   Timezone is completely ignored. Similar to the glibc `strptime` treatment of
+   this format code.
+   <br>
+   <br>
+   It is not possible to reliably convert from an abbreviation to an offset,
+   for example CDT can mean either Central Daylight Time (North America) or
+   China Daylight Time.
+*/
+
+#[cfg(feature = "unstable-locales")]
+extern crate alloc;
+
+#[cfg(feature = "unstable-locales")]
+use alloc::vec::Vec;
+
+#[cfg(feature = "unstable-locales")]
+use super::{locales, Locale};
+use super::{Fixed, InternalFixed, InternalInternal, Item, Numeric, Pad};
+
+#[cfg(feature = "unstable-locales")]
+type Fmt<'a> = Vec<Item<'a>>;
+#[cfg(not(feature = "unstable-locales"))]
+type Fmt<'a> = &'static [Item<'static>];
+
+static D_FMT: &[Item<'static>] =
+    &[num0!(Month), lit!("/"), num0!(Day), lit!("/"), num0!(YearMod100)];
+static D_T_FMT: &[Item<'static>] = &[
+    fix!(ShortWeekdayName),
+    sp!(" "),
+    fix!(ShortMonthName),
+    sp!(" "),
+    nums!(Day),
+    sp!(" "),
+    num0!(Hour),
+    lit!(":"),
+    num0!(Minute),
+    lit!(":"),
+    num0!(Second),
+    sp!(" "),
+    num0!(Year),
+];
+static T_FMT: &[Item<'static>] = &[num0!(Hour), lit!(":"), num0!(Minute), lit!(":"), num0!(Second)];
+
+/// Parsing iterator for `strftime`-like format strings.
+#[derive(Clone, Debug)]
+pub struct StrftimeItems<'a> {
+    /// Remaining portion of the string.
+    remainder: &'a str,
+    /// If the current specifier is composed of multiple formatting items (e.g. `%+`),
+    /// parser refers to the statically reconstructed slice of them.
+    /// If `recons` is not empty they have to be returned earlier than the `remainder`.
+    recons: Fmt<'a>,
+    /// Date format
+    d_fmt: Fmt<'a>,
+    /// Date and time format
+    d_t_fmt: Fmt<'a>,
+    /// Time format
+    t_fmt: Fmt<'a>,
+}
+
+impl<'a> StrftimeItems<'a> {
+    /// Creates a new parsing iterator from the `strftime`-like format string.
+    pub fn new(s: &'a str) -> StrftimeItems<'a> {
+        Self::with_remainer(s)
+    }
+
+    /// Creates a new parsing iterator from the `strftime`-like format string.
+    #[cfg(feature = "unstable-locales")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "unstable-locales")))]
+    pub fn new_with_locale(s: &'a str, locale: Locale) -> StrftimeItems<'a> {
+        let d_fmt = StrftimeItems::new(locales::d_fmt(locale)).collect();
+        let d_t_fmt = StrftimeItems::new(locales::d_t_fmt(locale)).collect();
+        let t_fmt = StrftimeItems::new(locales::t_fmt(locale)).collect();
+
+        StrftimeItems { remainder: s, recons: Vec::new(), d_fmt, d_t_fmt, t_fmt }
+    }
+
+    #[cfg(not(feature = "unstable-locales"))]
+    fn with_remainer(s: &'a str) -> StrftimeItems<'a> {
+        static FMT_NONE: &[Item<'static>; 0] = &[];
+
+        StrftimeItems {
+            remainder: s,
+            recons: FMT_NONE,
+            d_fmt: D_FMT,
+            d_t_fmt: D_T_FMT,
+            t_fmt: T_FMT,
+        }
+    }
+
+    #[cfg(feature = "unstable-locales")]
+    fn with_remainer(s: &'a str) -> StrftimeItems<'a> {
+        StrftimeItems {
+            remainder: s,
+            recons: Vec::new(),
+            d_fmt: D_FMT.to_vec(),
+            d_t_fmt: D_T_FMT.to_vec(),
+            t_fmt: T_FMT.to_vec(),
+        }
+    }
+}
+
+const HAVE_ALTERNATES: &str = "z";
+
+impl<'a> Iterator for StrftimeItems<'a> {
+    type Item = Item<'a>;
+
+    fn next(&mut self) -> Option<Item<'a>> {
+        // we have some reconstructed items to return
+        if !self.recons.is_empty() {
+            let item;
+            #[cfg(feature = "unstable-locales")]
+            {
+                item = self.recons.remove(0);
+            }
+            #[cfg(not(feature = "unstable-locales"))]
+            {
+                item = self.recons[0].clone();
+                self.recons = &self.recons[1..];
+            }
+            return Some(item);
+        }
+
+        match self.remainder.chars().next() {
+            // we are done
+            None => None,
+
+            // the next item is a specifier
+            Some('%') => {
+                self.remainder = &self.remainder[1..];
+
+                macro_rules! next {
+                    () => {
+                        match self.remainder.chars().next() {
+                            Some(x) => {
+                                self.remainder = &self.remainder[x.len_utf8()..];
+                                x
+                            }
+                            None => return Some(Item::Error), // premature end of string
+                        }
+                    };
+                }
+
+                let spec = next!();
+                let pad_override = match spec {
+                    '-' => Some(Pad::None),
+                    '0' => Some(Pad::Zero),
+                    '_' => Some(Pad::Space),
+                    _ => None,
+                };
+                let is_alternate = spec == '#';
+                let spec = if pad_override.is_some() || is_alternate { next!() } else { spec };
+                if is_alternate && !HAVE_ALTERNATES.contains(spec) {
+                    return Some(Item::Error);
+                }
+
+                macro_rules! recons {
+                    [$head:expr, $($tail:expr),+ $(,)*] => ({
+                        #[cfg(feature = "unstable-locales")]
+                        {
+                            self.recons.clear();
+                            $(self.recons.push($tail);)+
+                        }
+                        #[cfg(not(feature = "unstable-locales"))]
+                        {
+                            const RECONS: &'static [Item<'static>] = &[$($tail),+];
+                            self.recons = RECONS;
+                        }
+                        $head
+                    })
+                }
+
+                macro_rules! recons_from_slice {
+                    ($slice:expr) => {{
+                        #[cfg(feature = "unstable-locales")]
+                        {
+                            self.recons.clear();
+                            self.recons.extend_from_slice(&$slice[1..]);
+                        }
+                        #[cfg(not(feature = "unstable-locales"))]
+                        {
+                            self.recons = &$slice[1..];
+                        }
+                        $slice[0].clone()
+                    }};
+                }
+
+                let item = match spec {
+                    'A' => fix!(LongWeekdayName),
+                    'B' => fix!(LongMonthName),
+                    'C' => num0!(YearDiv100),
+                    'D' => {
+                        recons![num0!(Month), lit!("/"), num0!(Day), lit!("/"), num0!(YearMod100)]
+                    }
+                    'F' => recons![num0!(Year), lit!("-"), num0!(Month), lit!("-"), num0!(Day)],
+                    'G' => num0!(IsoYear),
+                    'H' => num0!(Hour),
+                    'I' => num0!(Hour12),
+                    'M' => num0!(Minute),
+                    'P' => fix!(LowerAmPm),
+                    'R' => recons![num0!(Hour), lit!(":"), num0!(Minute)],
+                    'S' => num0!(Second),
+                    'T' => recons![num0!(Hour), lit!(":"), num0!(Minute), lit!(":"), num0!(Second)],
+                    'U' => num0!(WeekFromSun),
+                    'V' => num0!(IsoWeek),
+                    'W' => num0!(WeekFromMon),
+                    'X' => recons_from_slice!(self.t_fmt),
+                    'Y' => num0!(Year),
+                    'Z' => fix!(TimezoneName),
+                    'a' => fix!(ShortWeekdayName),
+                    'b' | 'h' => fix!(ShortMonthName),
+                    'c' => recons_from_slice!(self.d_t_fmt),
+                    'd' => num0!(Day),
+                    'e' => nums!(Day),
+                    'f' => num0!(Nanosecond),
+                    'g' => num0!(IsoYearMod100),
+                    'j' => num0!(Ordinal),
+                    'k' => nums!(Hour),
+                    'l' => nums!(Hour12),
+                    'm' => num0!(Month),
+                    'n' => sp!("\n"),
+                    'p' => fix!(UpperAmPm),
+                    'r' => recons![
+                        num0!(Hour12),
+                        lit!(":"),
+                        num0!(Minute),
+                        lit!(":"),
+                        num0!(Second),
+                        sp!(" "),
+                        fix!(UpperAmPm)
+                    ],
+                    's' => num!(Timestamp),
+                    't' => sp!("\t"),
+                    'u' => num!(WeekdayFromMon),
+                    'v' => {
+                        recons![nums!(Day), lit!("-"), fix!(ShortMonthName), lit!("-"), num0!(Year)]
+                    }
+                    'w' => num!(NumDaysFromSun),
+                    'x' => recons_from_slice!(self.d_fmt),
+                    'y' => num0!(YearMod100),
+                    'z' => {
+                        if is_alternate {
+                            internal_fix!(TimezoneOffsetPermissive)
+                        } else {
+                            fix!(TimezoneOffset)
+                        }
+                    }
+                    '+' => fix!(RFC3339),
+                    ':' => {
+                        if self.remainder.starts_with("::z") {
+                            self.remainder = &self.remainder[3..];
+                            fix!(TimezoneOffsetTripleColon)
+                        } else if self.remainder.starts_with(":z") {
+                            self.remainder = &self.remainder[2..];
+                            fix!(TimezoneOffsetDoubleColon)
+                        } else if self.remainder.starts_with('z') {
+                            self.remainder = &self.remainder[1..];
+                            fix!(TimezoneOffsetColon)
+                        } else {
+                            Item::Error
+                        }
+                    }
+                    '.' => match next!() {
+                        '3' => match next!() {
+                            'f' => fix!(Nanosecond3),
+                            _ => Item::Error,
+                        },
+                        '6' => match next!() {
+                            'f' => fix!(Nanosecond6),
+                            _ => Item::Error,
+                        },
+                        '9' => match next!() {
+                            'f' => fix!(Nanosecond9),
+                            _ => Item::Error,
+                        },
+                        'f' => fix!(Nanosecond),
+                        _ => Item::Error,
+                    },
+                    '3' => match next!() {
+                        'f' => internal_fix!(Nanosecond3NoDot),
+                        _ => Item::Error,
+                    },
+                    '6' => match next!() {
+                        'f' => internal_fix!(Nanosecond6NoDot),
+                        _ => Item::Error,
+                    },
+                    '9' => match next!() {
+                        'f' => internal_fix!(Nanosecond9NoDot),
+                        _ => Item::Error,
+                    },
+                    '%' => lit!("%"),
+                    _ => Item::Error, // no such specifier
+                };
+
+                // adjust `item` if we have any padding modifier
+                if let Some(new_pad) = pad_override {
+                    match item {
+                        Item::Numeric(ref kind, _pad) if self.recons.is_empty() => {
+                            Some(Item::Numeric(kind.clone(), new_pad))
+                        }
+                        _ => Some(Item::Error), // no reconstructed or non-numeric item allowed
+                    }
+                } else {
+                    Some(item)
+                }
+            }
+
+            // the next item is space
+            Some(c) if c.is_whitespace() => {
+                // `%` is not a whitespace, so `c != '%'` is redundant
+                let nextspec = self
+                    .remainder
+                    .find(|c: char| !c.is_whitespace())
+                    .unwrap_or(self.remainder.len());
+                assert!(nextspec > 0);
+                let item = sp!(&self.remainder[..nextspec]);
+                self.remainder = &self.remainder[nextspec..];
+                Some(item)
+            }
+
+            // the next item is literal
+            _ => {
+                let nextspec = self
+                    .remainder
+                    .find(|c: char| c.is_whitespace() || c == '%')
+                    .unwrap_or(self.remainder.len());
+                assert!(nextspec > 0);
+                let item = lit!(&self.remainder[..nextspec]);
+                self.remainder = &self.remainder[nextspec..];
+                Some(item)
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+#[test]
+fn test_strftime_items() {
+    fn parse_and_collect(s: &str) -> Vec<Item<'_>> {
+        // map any error into `[Item::Error]`. useful for easy testing.
+        let items = StrftimeItems::new(s);
+        let items = items.map(|spec| if spec == Item::Error { None } else { Some(spec) });
+        items.collect::<Option<Vec<_>>>().unwrap_or_else(|| vec![Item::Error])
+    }
+
+    assert_eq!(parse_and_collect(""), []);
+    assert_eq!(parse_and_collect(" \t\n\r "), [sp!(" \t\n\r ")]);
+    assert_eq!(parse_and_collect("hello?"), [lit!("hello?")]);
+    assert_eq!(
+        parse_and_collect("a  b\t\nc"),
+        [lit!("a"), sp!("  "), lit!("b"), sp!("\t\n"), lit!("c")]
+    );
+    assert_eq!(parse_and_collect("100%%"), [lit!("100"), lit!("%")]);
+    assert_eq!(parse_and_collect("100%% ok"), [lit!("100"), lit!("%"), sp!(" "), lit!("ok")]);
+    assert_eq!(parse_and_collect("%%PDF-1.0"), [lit!("%"), lit!("PDF-1.0")]);
+    assert_eq!(
+        parse_and_collect("%Y-%m-%d"),
+        [num0!(Year), lit!("-"), num0!(Month), lit!("-"), num0!(Day)]
+    );
+    assert_eq!(parse_and_collect("[%F]"), parse_and_collect("[%Y-%m-%d]"));
+    assert_eq!(parse_and_collect("%m %d"), [num0!(Month), sp!(" "), num0!(Day)]);
+    assert_eq!(parse_and_collect("%"), [Item::Error]);
+    assert_eq!(parse_and_collect("%%"), [lit!("%")]);
+    assert_eq!(parse_and_collect("%%%"), [Item::Error]);
+    assert_eq!(parse_and_collect("%%%%"), [lit!("%"), lit!("%")]);
+    assert_eq!(parse_and_collect("foo%?"), [Item::Error]);
+    assert_eq!(parse_and_collect("bar%42"), [Item::Error]);
+    assert_eq!(parse_and_collect("quux% +"), [Item::Error]);
+    assert_eq!(parse_and_collect("%.Z"), [Item::Error]);
+    assert_eq!(parse_and_collect("%:Z"), [Item::Error]);
+    assert_eq!(parse_and_collect("%-Z"), [Item::Error]);
+    assert_eq!(parse_and_collect("%0Z"), [Item::Error]);
+    assert_eq!(parse_and_collect("%_Z"), [Item::Error]);
+    assert_eq!(parse_and_collect("%.j"), [Item::Error]);
+    assert_eq!(parse_and_collect("%:j"), [Item::Error]);
+    assert_eq!(parse_and_collect("%-j"), [num!(Ordinal)]);
+    assert_eq!(parse_and_collect("%0j"), [num0!(Ordinal)]);
+    assert_eq!(parse_and_collect("%_j"), [nums!(Ordinal)]);
+    assert_eq!(parse_and_collect("%.e"), [Item::Error]);
+    assert_eq!(parse_and_collect("%:e"), [Item::Error]);
+    assert_eq!(parse_and_collect("%-e"), [num!(Day)]);
+    assert_eq!(parse_and_collect("%0e"), [num0!(Day)]);
+    assert_eq!(parse_and_collect("%_e"), [nums!(Day)]);
+    assert_eq!(parse_and_collect("%z"), [fix!(TimezoneOffset)]);
+    assert_eq!(parse_and_collect("%#z"), [internal_fix!(TimezoneOffsetPermissive)]);
+    assert_eq!(parse_and_collect("%#m"), [Item::Error]);
+}
+
+#[cfg(test)]
+#[test]
+fn test_strftime_docs() {
+    use crate::NaiveDate;
+    use crate::{DateTime, FixedOffset, TimeZone, Timelike, Utc};
+
+    let dt = FixedOffset::east_opt(34200)
+        .unwrap()
+        .from_local_datetime(
+            &NaiveDate::from_ymd_opt(2001, 7, 8)
+                .unwrap()
+                .and_hms_nano_opt(0, 34, 59, 1_026_490_708)
+                .unwrap(),
+        )
+        .unwrap();
+
+    // date specifiers
+    assert_eq!(dt.format("%Y").to_string(), "2001");
+    assert_eq!(dt.format("%C").to_string(), "20");
+    assert_eq!(dt.format("%y").to_string(), "01");
+    assert_eq!(dt.format("%m").to_string(), "07");
+    assert_eq!(dt.format("%b").to_string(), "Jul");
+    assert_eq!(dt.format("%B").to_string(), "July");
+    assert_eq!(dt.format("%h").to_string(), "Jul");
+    assert_eq!(dt.format("%d").to_string(), "08");
+    assert_eq!(dt.format("%e").to_string(), " 8");
+    assert_eq!(dt.format("%e").to_string(), dt.format("%_d").to_string());
+    assert_eq!(dt.format("%a").to_string(), "Sun");
+    assert_eq!(dt.format("%A").to_string(), "Sunday");
+    assert_eq!(dt.format("%w").to_string(), "0");
+    assert_eq!(dt.format("%u").to_string(), "7");
+    assert_eq!(dt.format("%U").to_string(), "28");
+    assert_eq!(dt.format("%W").to_string(), "27");
+    assert_eq!(dt.format("%G").to_string(), "2001");
+    assert_eq!(dt.format("%g").to_string(), "01");
+    assert_eq!(dt.format("%V").to_string(), "27");
+    assert_eq!(dt.format("%j").to_string(), "189");
+    assert_eq!(dt.format("%D").to_string(), "07/08/01");
+    assert_eq!(dt.format("%x").to_string(), "07/08/01");
+    assert_eq!(dt.format("%F").to_string(), "2001-07-08");
+    assert_eq!(dt.format("%v").to_string(), " 8-Jul-2001");
+
+    // time specifiers
+    assert_eq!(dt.format("%H").to_string(), "00");
+    assert_eq!(dt.format("%k").to_string(), " 0");
+    assert_eq!(dt.format("%k").to_string(), dt.format("%_H").to_string());
+    assert_eq!(dt.format("%I").to_string(), "12");
+    assert_eq!(dt.format("%l").to_string(), "12");
+    assert_eq!(dt.format("%l").to_string(), dt.format("%_I").to_string());
+    assert_eq!(dt.format("%P").to_string(), "am");
+    assert_eq!(dt.format("%p").to_string(), "AM");
+    assert_eq!(dt.format("%M").to_string(), "34");
+    assert_eq!(dt.format("%S").to_string(), "60");
+    assert_eq!(dt.format("%f").to_string(), "026490708");
+    assert_eq!(dt.format("%.f").to_string(), ".026490708");
+    assert_eq!(dt.with_nanosecond(1_026_490_000).unwrap().format("%.f").to_string(), ".026490");
+    assert_eq!(dt.format("%.3f").to_string(), ".026");
+    assert_eq!(dt.format("%.6f").to_string(), ".026490");
+    assert_eq!(dt.format("%.9f").to_string(), ".026490708");
+    assert_eq!(dt.format("%3f").to_string(), "026");
+    assert_eq!(dt.format("%6f").to_string(), "026490");
+    assert_eq!(dt.format("%9f").to_string(), "026490708");
+    assert_eq!(dt.format("%R").to_string(), "00:34");
+    assert_eq!(dt.format("%T").to_string(), "00:34:60");
+    assert_eq!(dt.format("%X").to_string(), "00:34:60");
+    assert_eq!(dt.format("%r").to_string(), "12:34:60 AM");
+
+    // time zone specifiers
+    //assert_eq!(dt.format("%Z").to_string(), "ACST");
+    assert_eq!(dt.format("%z").to_string(), "+0930");
+    assert_eq!(dt.format("%:z").to_string(), "+09:30");
+    assert_eq!(dt.format("%::z").to_string(), "+09:30:00");
+    assert_eq!(dt.format("%:::z").to_string(), "+09");
+
+    // date & time specifiers
+    assert_eq!(dt.format("%c").to_string(), "Sun Jul  8 00:34:60 2001");
+    assert_eq!(dt.format("%+").to_string(), "2001-07-08T00:34:60.026490708+09:30");
+
+    assert_eq!(
+        dt.with_timezone(&Utc).format("%+").to_string(),
+        "2001-07-07T15:04:60.026490708+00:00"
+    );
+    assert_eq!(
+        dt.with_timezone(&Utc),
+        DateTime::parse_from_str("2001-07-07T15:04:60.026490708Z", "%+").unwrap()
+    );
+    assert_eq!(
+        dt.with_timezone(&Utc),
+        DateTime::parse_from_str("2001-07-07T15:04:60.026490708UTC", "%+").unwrap()
+    );
+    assert_eq!(
+        dt.with_timezone(&Utc),
+        DateTime::parse_from_str("2001-07-07t15:04:60.026490708utc", "%+").unwrap()
+    );
+
+    assert_eq!(
+        dt.with_nanosecond(1_026_490_000).unwrap().format("%+").to_string(),
+        "2001-07-08T00:34:60.026490+09:30"
+    );
+    assert_eq!(dt.format("%s").to_string(), "994518299");
+
+    // special specifiers
+    assert_eq!(dt.format("%t").to_string(), "\t");
+    assert_eq!(dt.format("%n").to_string(), "\n");
+    assert_eq!(dt.format("%%").to_string(), "%");
+}
+
+#[cfg(feature = "unstable-locales")]
+#[test]
+fn test_strftime_docs_localized() {
+    use crate::{FixedOffset, NaiveDate, TimeZone};
+
+    let dt = FixedOffset::east_opt(34200).unwrap().ymd_opt(2001, 7, 8).unwrap().and_hms_nano(
+        0,
+        34,
+        59,
+        1_026_490_708,
+    );
+
+    // date specifiers
+    assert_eq!(dt.format_localized("%b", Locale::fr_BE).to_string(), "jui");
+    assert_eq!(dt.format_localized("%B", Locale::fr_BE).to_string(), "juillet");
+    assert_eq!(dt.format_localized("%h", Locale::fr_BE).to_string(), "jui");
+    assert_eq!(dt.format_localized("%a", Locale::fr_BE).to_string(), "dim");
+    assert_eq!(dt.format_localized("%A", Locale::fr_BE).to_string(), "dimanche");
+    assert_eq!(dt.format_localized("%D", Locale::fr_BE).to_string(), "07/08/01");
+    assert_eq!(dt.format_localized("%x", Locale::fr_BE).to_string(), "08/07/01");
+    assert_eq!(dt.format_localized("%F", Locale::fr_BE).to_string(), "2001-07-08");
+    assert_eq!(dt.format_localized("%v", Locale::fr_BE).to_string(), " 8-jui-2001");
+
+    // time specifiers
+    assert_eq!(dt.format_localized("%P", Locale::fr_BE).to_string(), "");
+    assert_eq!(dt.format_localized("%p", Locale::fr_BE).to_string(), "");
+    assert_eq!(dt.format_localized("%R", Locale::fr_BE).to_string(), "00:34");
+    assert_eq!(dt.format_localized("%T", Locale::fr_BE).to_string(), "00:34:60");
+    assert_eq!(dt.format_localized("%X", Locale::fr_BE).to_string(), "00:34:60");
+    assert_eq!(dt.format_localized("%r", Locale::fr_BE).to_string(), "12:34:60 ");
+
+    // date & time specifiers
+    assert_eq!(
+        dt.format_localized("%c", Locale::fr_BE).to_string(),
+        "dim 08 jui 2001 00:34:60 +09:30"
+    );
+
+    let nd = NaiveDate::from_ymd_opt(2001, 7, 8).unwrap();
+
+    // date specifiers
+    assert_eq!(nd.format_localized("%b", Locale::de_DE).to_string(), "Jul");
+    assert_eq!(nd.format_localized("%B", Locale::de_DE).to_string(), "Juli");
+    assert_eq!(nd.format_localized("%h", Locale::de_DE).to_string(), "Jul");
+    assert_eq!(nd.format_localized("%a", Locale::de_DE).to_string(), "So");
+    assert_eq!(nd.format_localized("%A", Locale::de_DE).to_string(), "Sonntag");
+    assert_eq!(nd.format_localized("%D", Locale::de_DE).to_string(), "07/08/01");
+    assert_eq!(nd.format_localized("%x", Locale::de_DE).to_string(), "08.07.2001");
+    assert_eq!(nd.format_localized("%F", Locale::de_DE).to_string(), "2001-07-08");
+    assert_eq!(nd.format_localized("%v", Locale::de_DE).to_string(), " 8-Jul-2001");
+}

javascript-engine/external/chrono/src/lib.rs

@@ -0,0 +1,527 @@
+//! # Chrono: Date and Time for Rust
+//!
+//! It aims to be a feature-complete superset of
+//! the [time](https://github.com/rust-lang-deprecated/time) library.
+//! In particular,
+//!
+//! * Chrono strictly adheres to ISO 8601.
+//! * Chrono is timezone-aware by default, with separate timezone-naive types.
+//! * Chrono is space-optimal and (while not being the primary goal) reasonably efficient.
+//!
+//! There were several previous attempts to bring a good date and time library to Rust,
+//! which Chrono builds upon and should acknowledge:
+//!
+//! * [Initial research on
+//!    the wiki](https://github.com/rust-lang/rust-wiki-backup/blob/master/Lib-datetime.md)
+//! * Dietrich Epp's [datetime-rs](https://github.com/depp/datetime-rs)
+//! * Luis de Bethencourt's [rust-datetime](https://github.com/luisbg/rust-datetime)
+//!
+//! ### Features
+//!
+//! Chrono supports various runtime environments and operating systems, and has
+//! several features that may be enabled or disabled.
+//!
+//! Default features:
+//!
+//! - `alloc`: Enable features that depend on allocation (primarily string formatting)
+//! - `std`: Enables functionality that depends on the standard library. This
+//!   is a superset of `alloc` and adds interoperation with standard library types
+//!   and traits.
+//! - `clock`: Enables reading the system time (`now`) that depends on the standard library for
+//! UNIX-like operating systems and the Windows API (`winapi`) for Windows.
+//!
+//! Optional features:
+//!
+//! - [`serde`][]: Enable serialization/deserialization via serde.
+//! - `unstable-locales`: Enable localization. This adds various methods with a
+//!   `_localized` suffix. The implementation and API may change or even be
+//!   removed in a patch release. Feedback welcome.
+//!
+//! [`serde`]: https://github.com/serde-rs/serde
+//! [wasm-bindgen]: https://github.com/rustwasm/wasm-bindgen
+//!
+//! See the [cargo docs][] for examples of specifying features.
+//!
+//! [cargo docs]: https://doc.rust-lang.org/cargo/reference/specifying-dependencies.html#choosing-features
+//!
+//! ## Overview
+//!
+//! ### Duration
+//!
+//! Chrono currently uses its own [`Duration`] type to represent the magnitude
+//! of a time span. Since this has the same name as the newer, standard type for
+//! duration, the reference will refer this type as `OldDuration`.
+//!
+//! Note that this is an "accurate" duration represented as seconds and
+//! nanoseconds and does not represent "nominal" components such as days or
+//! months.
+//!
+//! When the `oldtime` feature is enabled, [`Duration`] is an alias for the
+//! [`time::Duration`](https://docs.rs/time/0.1.40/time/struct.Duration.html)
+//! type from v0.1 of the time crate. time v0.1 is deprecated, so new code
+//! should disable the `oldtime` feature and use the `chrono::Duration` type
+//! instead. The `oldtime` feature is enabled by default for backwards
+//! compatibility, but future versions of Chrono are likely to remove the
+//! feature entirely.
+//!
+//! Chrono does not yet natively support
+//! the standard [`Duration`](https://doc.rust-lang.org/std/time/struct.Duration.html) type,
+//! but it will be supported in the future.
+//! Meanwhile you can convert between two types with
+//! [`Duration::from_std`](https://docs.rs/time/0.1.40/time/struct.Duration.html#method.from_std)
+//! and
+//! [`Duration::to_std`](https://docs.rs/time/0.1.40/time/struct.Duration.html#method.to_std)
+//! methods.
+//!
+//! ### Date and Time
+//!
+//! Chrono provides a
+//! [**`DateTime`**](./struct.DateTime.html)
+//! type to represent a date and a time in a timezone.
+//!
+//! For more abstract moment-in-time tracking such as internal timekeeping
+//! that is unconcerned with timezones, consider
+//! [`time::SystemTime`](https://doc.rust-lang.org/std/time/struct.SystemTime.html),
+//! which tracks your system clock, or
+//! [`time::Instant`](https://doc.rust-lang.org/std/time/struct.Instant.html), which
+//! is an opaque but monotonically-increasing representation of a moment in time.
+//!
+//! `DateTime` is timezone-aware and must be constructed from
+//! the [**`TimeZone`**](./offset/trait.TimeZone.html) object,
+//! which defines how the local date is converted to and back from the UTC date.
+//! There are three well-known `TimeZone` implementations:
+//!
+//! * [**`Utc`**](./offset/struct.Utc.html) specifies the UTC time zone. It is most efficient.
+//!
+//! * [**`Local`**](./offset/struct.Local.html) specifies the system local time zone.
+//!
+//! * [**`FixedOffset`**](./offset/struct.FixedOffset.html) specifies
+//!   an arbitrary, fixed time zone such as UTC+09:00 or UTC-10:30.
+//!   This often results from the parsed textual date and time.
+//!   Since it stores the most information and does not depend on the system environment,
+//!   you would want to normalize other `TimeZone`s into this type.
+//!
+//! `DateTime`s with different `TimeZone` types are distinct and do not mix,
+//! but can be converted to each other using
+//! the [`DateTime::with_timezone`](./struct.DateTime.html#method.with_timezone) method.
+//!
+//! You can get the current date and time in the UTC time zone
+//! ([`Utc::now()`](./offset/struct.Utc.html#method.now))
+//! or in the local time zone
+//! ([`Local::now()`](./offset/struct.Local.html#method.now)).
+//!
+//! ```rust
+//! use chrono::prelude::*;
+//!
+//! let utc: DateTime<Utc> = Utc::now();       // e.g. `2014-11-28T12:45:59.324310806Z`
+//! let local: DateTime<Local> = Local::now(); // e.g. `2014-11-28T21:45:59.324310806+09:00`
+//! # let _ = utc; let _ = local;
+//! ```
+//!
+//! Alternatively, you can create your own date and time.
+//! This is a bit verbose due to Rust's lack of function and method overloading,
+//! but in turn we get a rich combination of initialization methods.
+//!
+//! ```rust
+//! use chrono::prelude::*;
+//! use chrono::offset::LocalResult;
+//!
+//! let dt = Utc.with_ymd_and_hms(2014, 7, 8, 9, 10, 11).unwrap(); // `2014-07-08T09:10:11Z`
+//! // July 8 is 188th day of the year 2014 (`o` for "ordinal")
+//! assert_eq!(dt, Utc.yo(2014, 189).and_hms_opt(9, 10, 11).unwrap());
+//! // July 8 is Tuesday in ISO week 28 of the year 2014.
+//! assert_eq!(dt, Utc.isoywd(2014, 28, Weekday::Tue).and_hms_opt(9, 10, 11).unwrap());
+//!
+//! let dt = NaiveDate::from_ymd_opt(2014, 7, 8).unwrap().and_hms_milli_opt(9, 10, 11, 12).unwrap().and_local_timezone(Utc).unwrap(); // `2014-07-08T09:10:11.012Z`
+//! assert_eq!(dt, NaiveDate::from_ymd_opt(2014, 7, 8).unwrap().and_hms_micro_opt(9, 10, 11, 12_000).unwrap().and_local_timezone(Utc).unwrap());
+//! assert_eq!(dt, NaiveDate::from_ymd_opt(2014, 7, 8).unwrap().and_hms_nano_opt(9, 10, 11, 12_000_000).unwrap().and_local_timezone(Utc).unwrap());
+//!
+//! // dynamic verification
+//! assert_eq!(Utc.ymd_opt(2014, 7, 8).and_hms_opt(21, 15, 33),
+//!            LocalResult::Single(Utc.with_ymd_and_hms(2014, 7, 8, 21, 15, 33).unwrap()));
+//! assert_eq!(Utc.ymd_opt(2014, 7, 8).and_hms_opt(80, 15, 33), LocalResult::None);
+//! assert_eq!(Utc.ymd_opt(2014, 7, 38).and_hms_opt(21, 15, 33), LocalResult::None);
+//!
+//! // other time zone objects can be used to construct a local datetime.
+//! // obviously, `local_dt` is normally different from `dt`, but `fixed_dt` should be identical.
+//! let local_dt = Local.from_local_datetime(&NaiveDate::from_ymd_opt(2014, 7, 8).unwrap().and_hms_milli_opt(9, 10, 11, 12).unwrap()).unwrap();
+//! let fixed_dt = FixedOffset::east_opt(9 * 3600).unwrap().from_local_datetime(&NaiveDate::from_ymd_opt(2014, 7, 8).unwrap().and_hms_milli_opt(18, 10, 11, 12).unwrap()).unwrap();
+//! assert_eq!(dt, fixed_dt);
+//! # let _ = local_dt;
+//! ```
+//!
+//! Various properties are available to the date and time, and can be altered individually.
+//! Most of them are defined in the traits [`Datelike`](./trait.Datelike.html) and
+//! [`Timelike`](./trait.Timelike.html) which you should `use` before.
+//! Addition and subtraction is also supported.
+//! The following illustrates most supported operations to the date and time:
+//!
+//! ```rust
+//! use chrono::prelude::*;
+//! use chrono::Duration;
+//!
+//! // assume this returned `2014-11-28T21:45:59.324310806+09:00`:
+//! let dt = FixedOffset::east_opt(9*3600).unwrap().from_local_datetime(&NaiveDate::from_ymd_opt(2014, 11, 28).unwrap().and_hms_nano_opt(21, 45, 59, 324310806).unwrap()).unwrap();
+//!
+//! // property accessors
+//! assert_eq!((dt.year(), dt.month(), dt.day()), (2014, 11, 28));
+//! assert_eq!((dt.month0(), dt.day0()), (10, 27)); // for unfortunate souls
+//! assert_eq!((dt.hour(), dt.minute(), dt.second()), (21, 45, 59));
+//! assert_eq!(dt.weekday(), Weekday::Fri);
+//! assert_eq!(dt.weekday().number_from_monday(), 5); // Mon=1, ..., Sun=7
+//! assert_eq!(dt.ordinal(), 332); // the day of year
+//! assert_eq!(dt.num_days_from_ce(), 735565); // the number of days from and including Jan 1, 1
+//!
+//! // time zone accessor and manipulation
+//! assert_eq!(dt.offset().fix().local_minus_utc(), 9 * 3600);
+//! assert_eq!(dt.timezone(), FixedOffset::east_opt(9 * 3600).unwrap());
+//! assert_eq!(dt.with_timezone(&Utc), NaiveDate::from_ymd_opt(2014, 11, 28).unwrap().and_hms_nano_opt(12, 45, 59, 324310806).unwrap().and_local_timezone(Utc).unwrap());
+//!
+//! // a sample of property manipulations (validates dynamically)
+//! assert_eq!(dt.with_day(29).unwrap().weekday(), Weekday::Sat); // 2014-11-29 is Saturday
+//! assert_eq!(dt.with_day(32), None);
+//! assert_eq!(dt.with_year(-300).unwrap().num_days_from_ce(), -109606); // November 29, 301 BCE
+//!
+//! // arithmetic operations
+//! let dt1 = Utc.with_ymd_and_hms(2014, 11, 14, 8, 9, 10).unwrap();
+//! let dt2 = Utc.with_ymd_and_hms(2014, 11, 14, 10, 9, 8).unwrap();
+//! assert_eq!(dt1.signed_duration_since(dt2), Duration::seconds(-2 * 3600 + 2));
+//! assert_eq!(dt2.signed_duration_since(dt1), Duration::seconds(2 * 3600 - 2));
+//! assert_eq!(Utc.with_ymd_and_hms(1970, 1, 1, 0, 0, 0).unwrap() + Duration::seconds(1_000_000_000),
+//!            Utc.with_ymd_and_hms(2001, 9, 9, 1, 46, 40).unwrap());
+//! assert_eq!(Utc.with_ymd_and_hms(1970, 1, 1, 0, 0, 0).unwrap() - Duration::seconds(1_000_000_000),
+//!            Utc.with_ymd_and_hms(1938, 4, 24, 22, 13, 20).unwrap());
+//! ```
+//!
+//! ### Formatting and Parsing
+//!
+//! Formatting is done via the [`format`](./struct.DateTime.html#method.format) method,
+//! which format is equivalent to the familiar `strftime` format.
+//!
+//! See [`format::strftime`](./format/strftime/index.html#specifiers)
+//! documentation for full syntax and list of specifiers.
+//!
+//! The default `to_string` method and `{:?}` specifier also give a reasonable representation.
+//! Chrono also provides [`to_rfc2822`](./struct.DateTime.html#method.to_rfc2822) and
+//! [`to_rfc3339`](./struct.DateTime.html#method.to_rfc3339) methods
+//! for well-known formats.
+//!
+//! Chrono now also provides date formatting in almost any language without the
+//! help of an additional C library. This functionality is under the feature
+//! `unstable-locales`:
+//!
+//! ```toml
+//! chrono = { version = "0.4", features = ["unstable-locales"] }
+//! ```
+//!
+//! The `unstable-locales` feature requires and implies at least the `alloc` feature.
+//!
+//! ```rust
+//! use chrono::prelude::*;
+//!
+//! # #[cfg(feature = "unstable-locales")]
+//! # fn test() {
+//! let dt = Utc.with_ymd_and_hms(2014, 11, 28, 12, 0, 9).unwrap();
+//! assert_eq!(dt.format("%Y-%m-%d %H:%M:%S").to_string(), "2014-11-28 12:00:09");
+//! assert_eq!(dt.format("%a %b %e %T %Y").to_string(), "Fri Nov 28 12:00:09 2014");
+//! assert_eq!(dt.format_localized("%A %e %B %Y, %T", Locale::fr_BE).to_string(), "vendredi 28 novembre 2014, 12:00:09");
+//!
+//! assert_eq!(dt.format("%a %b %e %T %Y").to_string(), dt.format("%c").to_string());
+//! assert_eq!(dt.to_string(), "2014-11-28 12:00:09 UTC");
+//! assert_eq!(dt.to_rfc2822(), "Fri, 28 Nov 2014 12:00:09 +0000");
+//! assert_eq!(dt.to_rfc3339(), "2014-11-28T12:00:09+00:00");
+//! assert_eq!(format!("{:?}", dt), "2014-11-28T12:00:09Z");
+//!
+//! // Note that milli/nanoseconds are only printed if they are non-zero
+//! let dt_nano = NaiveDate::from_ymd_opt(2014, 11, 28).unwrap().and_hms_nano_opt(12, 0, 9, 1).unwrap().and_local_timezone(Utc).unwrap();
+//! assert_eq!(format!("{:?}", dt_nano), "2014-11-28T12:00:09.000000001Z");
+//! # }
+//! # #[cfg(not(feature = "unstable-locales"))]
+//! # fn test() {}
+//! # if cfg!(feature = "unstable-locales") {
+//! #    test();
+//! # }
+//! ```
+//!
+//! Parsing can be done with three methods:
+//!
+//! 1. The standard [`FromStr`](https://doc.rust-lang.org/std/str/trait.FromStr.html) trait
+//!    (and [`parse`](https://doc.rust-lang.org/std/primitive.str.html#method.parse) method
+//!    on a string) can be used for parsing `DateTime<FixedOffset>`, `DateTime<Utc>` and
+//!    `DateTime<Local>` values. This parses what the `{:?}`
+//!    ([`std::fmt::Debug`](https://doc.rust-lang.org/std/fmt/trait.Debug.html))
+//!    format specifier prints, and requires the offset to be present.
+//!
+//! 2. [`DateTime::parse_from_str`](./struct.DateTime.html#method.parse_from_str) parses
+//!    a date and time with offsets and returns `DateTime<FixedOffset>`.
+//!    This should be used when the offset is a part of input and the caller cannot guess that.
+//!    It *cannot* be used when the offset can be missing.
+//!    [`DateTime::parse_from_rfc2822`](./struct.DateTime.html#method.parse_from_rfc2822)
+//!    and
+//!    [`DateTime::parse_from_rfc3339`](./struct.DateTime.html#method.parse_from_rfc3339)
+//!    are similar but for well-known formats.
+//!
+//! 3. [`Offset::datetime_from_str`](./offset/trait.TimeZone.html#method.datetime_from_str) is
+//!    similar but returns `DateTime` of given offset.
+//!    When the explicit offset is missing from the input, it simply uses given offset.
+//!    It issues an error when the input contains an explicit offset different
+//!    from the current offset.
+//!
+//! More detailed control over the parsing process is available via
+//! [`format`](./format/index.html) module.
+//!
+//! ```rust
+//! use chrono::prelude::*;
+//!
+//! let dt = Utc.with_ymd_and_hms(2014, 11, 28, 12, 0, 9).unwrap();
+//! let fixed_dt = dt.with_timezone(&FixedOffset::east_opt(9*3600).unwrap());
+//!
+//! // method 1
+//! assert_eq!("2014-11-28T12:00:09Z".parse::<DateTime<Utc>>(), Ok(dt.clone()));
+//! assert_eq!("2014-11-28T21:00:09+09:00".parse::<DateTime<Utc>>(), Ok(dt.clone()));
+//! assert_eq!("2014-11-28T21:00:09+09:00".parse::<DateTime<FixedOffset>>(), Ok(fixed_dt.clone()));
+//!
+//! // method 2
+//! assert_eq!(DateTime::parse_from_str("2014-11-28 21:00:09 +09:00", "%Y-%m-%d %H:%M:%S %z"),
+//!            Ok(fixed_dt.clone()));
+//! assert_eq!(DateTime::parse_from_rfc2822("Fri, 28 Nov 2014 21:00:09 +0900"),
+//!            Ok(fixed_dt.clone()));
+//! assert_eq!(DateTime::parse_from_rfc3339("2014-11-28T21:00:09+09:00"), Ok(fixed_dt.clone()));
+//!
+//! // method 3
+//! assert_eq!(Utc.datetime_from_str("2014-11-28 12:00:09", "%Y-%m-%d %H:%M:%S"), Ok(dt.clone()));
+//! assert_eq!(Utc.datetime_from_str("Fri Nov 28 12:00:09 2014", "%a %b %e %T %Y"), Ok(dt.clone()));
+//!
+//! // oops, the year is missing!
+//! assert!(Utc.datetime_from_str("Fri Nov 28 12:00:09", "%a %b %e %T %Y").is_err());
+//! // oops, the format string does not include the year at all!
+//! assert!(Utc.datetime_from_str("Fri Nov 28 12:00:09", "%a %b %e %T").is_err());
+//! // oops, the weekday is incorrect!
+//! assert!(Utc.datetime_from_str("Sat Nov 28 12:00:09 2014", "%a %b %e %T %Y").is_err());
+//! ```
+//!
+//! Again : See [`format::strftime`](./format/strftime/index.html#specifiers)
+//! documentation for full syntax and list of specifiers.
+//!
+//! ### Conversion from and to EPOCH timestamps
+//!
+//! Use [`Utc.timestamp(seconds, nanoseconds)`](./offset/trait.TimeZone.html#method.timestamp)
+//! to construct a [`DateTime<Utc>`](./struct.DateTime.html) from a UNIX timestamp
+//! (seconds, nanoseconds that passed since January 1st 1970).
+//!
+//! Use [`DateTime.timestamp`](./struct.DateTime.html#method.timestamp) to get the timestamp (in seconds)
+//! from a [`DateTime`](./struct.DateTime.html). Additionally, you can use
+//! [`DateTime.timestamp_subsec_nanos`](./struct.DateTime.html#method.timestamp_subsec_nanos)
+//! to get the number of additional number of nanoseconds.
+//!
+//! ```rust
+//! // We need the trait in scope to use Utc::timestamp().
+//! use chrono::{DateTime, TimeZone, Utc};
+//!
+//! // Construct a datetime from epoch:
+//! let dt = Utc.timestamp(1_500_000_000, 0);
+//! assert_eq!(dt.to_rfc2822(), "Fri, 14 Jul 2017 02:40:00 +0000");
+//!
+//! // Get epoch value from a datetime:
+//! let dt = DateTime::parse_from_rfc2822("Fri, 14 Jul 2017 02:40:00 +0000").unwrap();
+//! assert_eq!(dt.timestamp(), 1_500_000_000);
+//! ```
+//!
+//! ### Individual date
+//!
+//! Chrono also provides an individual date type ([**`Date`**](./struct.Date.html)).
+//! It also has time zones attached, and have to be constructed via time zones.
+//! Most operations available to `DateTime` are also available to `Date` whenever appropriate.
+//!
+//! ```rust
+//! use chrono::prelude::*;
+//! use chrono::offset::LocalResult;
+//!
+//! # // these *may* fail, but only very rarely. just rerun the test if you were that unfortunate ;)
+//! assert_eq!(Utc::today(), Utc::now().date());
+//! assert_eq!(Local::today(), Local::now().date());
+//!
+//! assert_eq!(Utc.ymd_opt(2014, 11, 28).unwrap().weekday(), Weekday::Fri);
+//! assert_eq!(Utc.ymd_opt(2014, 11, 31), LocalResult::None);
+//! assert_eq!(NaiveDate::from_ymd_opt(2014, 11, 28).unwrap().and_hms_milli_opt(7, 8, 9, 10).unwrap().and_local_timezone(Utc).unwrap().format("%H%M%S").to_string(),
+//!            "070809");
+//! ```
+//!
+//! There is no timezone-aware `Time` due to the lack of usefulness and also the complexity.
+//!
+//! `DateTime` has [`date`](./struct.DateTime.html#method.date) method
+//! which returns a `Date` which represents its date component.
+//! There is also a [`time`](./struct.DateTime.html#method.time) method,
+//! which simply returns a naive local time described below.
+//!
+//! ### Naive date and time
+//!
+//! Chrono provides naive counterparts to `Date`, (non-existent) `Time` and `DateTime`
+//! as [**`NaiveDate`**](./naive/struct.NaiveDate.html),
+//! [**`NaiveTime`**](./naive/struct.NaiveTime.html) and
+//! [**`NaiveDateTime`**](./naive/struct.NaiveDateTime.html) respectively.
+//!
+//! They have almost equivalent interfaces as their timezone-aware twins,
+//! but are not associated to time zones obviously and can be quite low-level.
+//! They are mostly useful for building blocks for higher-level types.
+//!
+//! Timezone-aware `DateTime` and `Date` types have two methods returning naive versions:
+//! [`naive_local`](./struct.DateTime.html#method.naive_local) returns
+//! a view to the naive local time,
+//! and [`naive_utc`](./struct.DateTime.html#method.naive_utc) returns
+//! a view to the naive UTC time.
+//!
+//! ## Limitations
+//!
+//! Only proleptic Gregorian calendar (i.e. extended to support older dates) is supported.
+//! Be very careful if you really have to deal with pre-20C dates, they can be in Julian or others.
+//!
+//! Date types are limited in about +/- 262,000 years from the common epoch.
+//! Time types are limited in the nanosecond accuracy.
+//!
+//! [Leap seconds are supported in the representation but
+//! Chrono doesn't try to make use of them](./naive/struct.NaiveTime.html#leap-second-handling).
+//! (The main reason is that leap seconds are not really predictable.)
+//! Almost *every* operation over the possible leap seconds will ignore them.
+//! Consider using `NaiveDateTime` with the implicit TAI (International Atomic Time) scale
+//! if you want.
+//!
+//! Chrono inherently does not support an inaccurate or partial date and time representation.
+//! Any operation that can be ambiguous will return `None` in such cases.
+//! For example, "a month later" of 2014-01-30 is not well-defined
+//! and consequently `Utc.ymd_opt(2014, 1, 30).unwrap().with_month(2)` returns `None`.
+//!
+//! Non ISO week handling is not yet supported.
+//! For now you can use the [chrono_ext](https://crates.io/crates/chrono_ext)
+//! crate ([sources](https://github.com/bcourtine/chrono-ext/)).
+//!
+//! Advanced time zone handling is not yet supported.
+//! For now you can try the [Chrono-tz](https://github.com/chronotope/chrono-tz/) crate instead.
+
+#![doc(html_root_url = "https://docs.rs/chrono/latest/")]
+#![cfg_attr(feature = "bench", feature(test))] // lib stability features as per RFC #507
+#![deny(missing_docs)]
+#![deny(missing_debug_implementations)]
+#![warn(unreachable_pub)]
+#![deny(dead_code)]
+#![cfg_attr(not(any(feature = "std", test)), no_std)]
+// can remove this if/when rustc-serialize support is removed
+// keeps clippy happy in the meantime
+#![cfg_attr(feature = "rustc-serialize", allow(deprecated))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
+
+#[cfg(feature = "oldtime")]
+#[cfg_attr(docsrs, doc(cfg(feature = "oldtime")))]
+extern crate time as oldtime;
+#[cfg(not(feature = "oldtime"))]
+mod oldtime;
+// this reexport is to aid the transition and should not be in the prelude!
+pub use oldtime::{Duration, OutOfRangeError};
+
+#[cfg(feature = "__doctest")]
+#[cfg_attr(feature = "__doctest", cfg(doctest))]
+use doc_comment::doctest;
+
+#[cfg(feature = "__doctest")]
+#[cfg_attr(feature = "__doctest", cfg(doctest))]
+doctest!("../README.md");
+
+/// A convenience module appropriate for glob imports (`use chrono::prelude::*;`).
+pub mod prelude {
+    #[doc(no_inline)]
+    #[allow(deprecated)]
+    pub use crate::Date;
+    #[cfg(feature = "clock")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "clock")))]
+    #[doc(no_inline)]
+    pub use crate::Local;
+    #[cfg(feature = "unstable-locales")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "unstable-locales")))]
+    #[doc(no_inline)]
+    pub use crate::Locale;
+    #[doc(no_inline)]
+    pub use crate::SubsecRound;
+    #[doc(no_inline)]
+    pub use crate::{DateTime, SecondsFormat};
+    #[doc(no_inline)]
+    pub use crate::{Datelike, Month, Timelike, Weekday};
+    #[doc(no_inline)]
+    pub use crate::{FixedOffset, Utc};
+    #[doc(no_inline)]
+    pub use crate::{NaiveDate, NaiveDateTime, NaiveTime};
+    #[doc(no_inline)]
+    pub use crate::{Offset, TimeZone};
+}
+
+mod date;
+#[allow(deprecated)]
+pub use date::{Date, MAX_DATE, MIN_DATE};
+
+mod datetime;
+#[cfg(feature = "rustc-serialize")]
+#[cfg_attr(docsrs, doc(cfg(feature = "rustc-serialize")))]
+pub use datetime::rustc_serialize::TsSeconds;
+#[allow(deprecated)]
+pub use datetime::{DateTime, SecondsFormat, MAX_DATETIME, MIN_DATETIME};
+
+pub mod format;
+/// L10n locales.
+#[cfg(feature = "unstable-locales")]
+#[cfg_attr(docsrs, doc(cfg(feature = "unstable-locales")))]
+pub use format::Locale;
+pub use format::{ParseError, ParseResult};
+
+pub mod naive;
+#[doc(no_inline)]
+pub use naive::{Days, IsoWeek, NaiveDate, NaiveDateTime, NaiveTime, NaiveWeek};
+
+pub mod offset;
+#[cfg(feature = "clock")]
+#[cfg_attr(docsrs, doc(cfg(feature = "clock")))]
+#[doc(no_inline)]
+pub use offset::Local;
+#[doc(no_inline)]
+pub use offset::{FixedOffset, LocalResult, Offset, TimeZone, Utc};
+
+mod round;
+pub use round::{DurationRound, RoundingError, SubsecRound};
+
+mod weekday;
+pub use weekday::{ParseWeekdayError, Weekday};
+
+mod month;
+pub use month::{Month, Months, ParseMonthError};
+
+mod traits;
+pub use traits::{Datelike, Timelike};
+
+#[cfg(feature = "__internal_bench")]
+#[doc(hidden)]
+pub use naive::__BenchYearFlags;
+
+/// Serialization/Deserialization with serde.
+///
+/// This module provides default implementations for `DateTime` using the [RFC 3339][1] format and various
+/// alternatives for use with serde's [`with` annotation][1].
+///
+/// *Available on crate feature 'serde' only.*
+///
+/// [1]: https://tools.ietf.org/html/rfc3339
+/// [2]: https://serde.rs/attributes.html#field-attributes
+#[cfg(feature = "serde")]
+#[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
+pub mod serde {
+    pub use super::datetime::serde::*;
+}
+
+/// MSRV 1.42
+#[cfg(test)]
+#[macro_export]
+macro_rules! matches {
+    ($expression:expr, $(|)? $( $pattern:pat )|+ $( if $guard: expr )? $(,)?) => {
+        match $expression {
+            $( $pattern )|+ $( if $guard )? => true,
+            _ => false
+        }
+    }
+}

javascript-engine/external/chrono/src/month.rs

@@ -0,0 +1,355 @@
+use core::fmt;
+
+#[cfg(feature = "rkyv")]
+use rkyv::{Archive, Deserialize, Serialize};
+
+/// The month of the year.
+///
+/// This enum is just a convenience implementation.
+/// The month in dates created by DateLike objects does not return this enum.
+///
+/// It is possible to convert from a date to a month independently
+/// ```
+/// use num_traits::FromPrimitive;
+/// use chrono::prelude::*;
+/// let date = Utc.with_ymd_and_hms(2019, 10, 28, 9, 10, 11).unwrap();
+/// // `2019-10-28T09:10:11Z`
+/// let month = Month::from_u32(date.month());
+/// assert_eq!(month, Some(Month::October))
+/// ```
+/// Or from a Month to an integer usable by dates
+/// ```
+/// # use chrono::prelude::*;
+/// let month = Month::January;
+/// let dt = Utc.with_ymd_and_hms(2019, month.number_from_month(), 28, 9, 10, 11).unwrap();
+/// assert_eq!((dt.year(), dt.month(), dt.day()), (2019, 1, 28));
+/// ```
+/// Allows mapping from and to month, from 1-January to 12-December.
+/// Can be Serialized/Deserialized with serde
+// Actual implementation is zero-indexed, API intended as 1-indexed for more intuitive behavior.
+#[derive(PartialEq, Eq, Copy, Clone, Debug, Hash)]
+#[cfg_attr(feature = "rustc-serialize", derive(RustcEncodable, RustcDecodable))]
+#[cfg_attr(feature = "rkyv", derive(Archive, Deserialize, Serialize))]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
+pub enum Month {
+    /// January
+    January = 0,
+    /// February
+    February = 1,
+    /// March
+    March = 2,
+    /// April
+    April = 3,
+    /// May
+    May = 4,
+    /// June
+    June = 5,
+    /// July
+    July = 6,
+    /// August
+    August = 7,
+    /// September
+    September = 8,
+    /// October
+    October = 9,
+    /// November
+    November = 10,
+    /// December
+    December = 11,
+}
+
+impl Month {
+    /// The next month.
+    ///
+    /// `m`:        | `January`  | `February` | `...` | `December`
+    /// ----------- | ---------  | ---------- | --- | ---------
+    /// `m.succ()`: | `February` | `March`    | `...` | `January`
+    #[inline]
+    pub fn succ(&self) -> Month {
+        match *self {
+            Month::January => Month::February,
+            Month::February => Month::March,
+            Month::March => Month::April,
+            Month::April => Month::May,
+            Month::May => Month::June,
+            Month::June => Month::July,
+            Month::July => Month::August,
+            Month::August => Month::September,
+            Month::September => Month::October,
+            Month::October => Month::November,
+            Month::November => Month::December,
+            Month::December => Month::January,
+        }
+    }
+
+    /// The previous month.
+    ///
+    /// `m`:        | `January`  | `February` | `...` | `December`
+    /// ----------- | ---------  | ---------- | --- | ---------
+    /// `m.pred()`: | `December` | `January`  | `...` | `November`
+    #[inline]
+    pub fn pred(&self) -> Month {
+        match *self {
+            Month::January => Month::December,
+            Month::February => Month::January,
+            Month::March => Month::February,
+            Month::April => Month::March,
+            Month::May => Month::April,
+            Month::June => Month::May,
+            Month::July => Month::June,
+            Month::August => Month::July,
+            Month::September => Month::August,
+            Month::October => Month::September,
+            Month::November => Month::October,
+            Month::December => Month::November,
+        }
+    }
+
+    /// Returns a month-of-year number starting from January = 1.
+    ///
+    /// `m`:                     | `January` | `February` | `...` | `December`
+    /// -------------------------| --------- | ---------- | --- | -----
+    /// `m.number_from_month()`: | 1         | 2          | `...` | 12
+    #[inline]
+    pub fn number_from_month(&self) -> u32 {
+        match *self {
+            Month::January => 1,
+            Month::February => 2,
+            Month::March => 3,
+            Month::April => 4,
+            Month::May => 5,
+            Month::June => 6,
+            Month::July => 7,
+            Month::August => 8,
+            Month::September => 9,
+            Month::October => 10,
+            Month::November => 11,
+            Month::December => 12,
+        }
+    }
+
+    /// Get the name of the month
+    ///
+    /// ```
+    /// use chrono::Month;
+    ///
+    /// assert_eq!(Month::January.name(), "January")
+    /// ```
+    pub fn name(&self) -> &'static str {
+        match *self {
+            Month::January => "January",
+            Month::February => "February",
+            Month::March => "March",
+            Month::April => "April",
+            Month::May => "May",
+            Month::June => "June",
+            Month::July => "July",
+            Month::August => "August",
+            Month::September => "September",
+            Month::October => "October",
+            Month::November => "November",
+            Month::December => "December",
+        }
+    }
+}
+
+impl num_traits::FromPrimitive for Month {
+    /// Returns an `Option<Month>` from a i64, assuming a 1-index, January = 1.
+    ///
+    /// `Month::from_i64(n: i64)`: | `1`                  | `2`                   | ... | `12`
+    /// ---------------------------| -------------------- | --------------------- | ... | -----
+    /// ``:                        | Some(Month::January) | Some(Month::February) | ... | Some(Month::December)
+
+    #[inline]
+    fn from_u64(n: u64) -> Option<Month> {
+        Self::from_u32(n as u32)
+    }
+
+    #[inline]
+    fn from_i64(n: i64) -> Option<Month> {
+        Self::from_u32(n as u32)
+    }
+
+    #[inline]
+    fn from_u32(n: u32) -> Option<Month> {
+        match n {
+            1 => Some(Month::January),
+            2 => Some(Month::February),
+            3 => Some(Month::March),
+            4 => Some(Month::April),
+            5 => Some(Month::May),
+            6 => Some(Month::June),
+            7 => Some(Month::July),
+            8 => Some(Month::August),
+            9 => Some(Month::September),
+            10 => Some(Month::October),
+            11 => Some(Month::November),
+            12 => Some(Month::December),
+            _ => None,
+        }
+    }
+}
+
+/// A duration in calendar months
+#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
+pub struct Months(pub(crate) u32);
+
+impl Months {
+    /// Construct a new `Months` from a number of months
+    pub fn new(num: u32) -> Self {
+        Self(num)
+    }
+}
+
+/// An error resulting from reading `<Month>` value with `FromStr`.
+#[derive(Clone, PartialEq, Eq)]
+pub struct ParseMonthError {
+    pub(crate) _dummy: (),
+}
+
+impl fmt::Debug for ParseMonthError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "ParseMonthError {{ .. }}")
+    }
+}
+
+#[cfg(feature = "serde")]
+#[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
+mod month_serde {
+    use super::Month;
+    use serde::{de, ser};
+
+    use core::fmt;
+
+    impl ser::Serialize for Month {
+        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+        where
+            S: ser::Serializer,
+        {
+            serializer.collect_str(self.name())
+        }
+    }
+
+    struct MonthVisitor;
+
+    impl<'de> de::Visitor<'de> for MonthVisitor {
+        type Value = Month;
+
+        fn expecting(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            f.write_str("Month")
+        }
+
+        fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
+        where
+            E: de::Error,
+        {
+            value.parse().map_err(|_| E::custom("short (3-letter) or full month names expected"))
+        }
+    }
+
+    impl<'de> de::Deserialize<'de> for Month {
+        fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+        where
+            D: de::Deserializer<'de>,
+        {
+            deserializer.deserialize_str(MonthVisitor)
+        }
+    }
+
+    #[test]
+    fn test_serde_serialize() {
+        use serde_json::to_string;
+        use Month::*;
+
+        let cases: Vec<(Month, &str)> = vec![
+            (January, "\"January\""),
+            (February, "\"February\""),
+            (March, "\"March\""),
+            (April, "\"April\""),
+            (May, "\"May\""),
+            (June, "\"June\""),
+            (July, "\"July\""),
+            (August, "\"August\""),
+            (September, "\"September\""),
+            (October, "\"October\""),
+            (November, "\"November\""),
+            (December, "\"December\""),
+        ];
+
+        for (month, expected_str) in cases {
+            let string = to_string(&month).unwrap();
+            assert_eq!(string, expected_str);
+        }
+    }
+
+    #[test]
+    fn test_serde_deserialize() {
+        use serde_json::from_str;
+        use Month::*;
+
+        let cases: Vec<(&str, Month)> = vec![
+            ("\"january\"", January),
+            ("\"jan\"", January),
+            ("\"FeB\"", February),
+            ("\"MAR\"", March),
+            ("\"mar\"", March),
+            ("\"april\"", April),
+            ("\"may\"", May),
+            ("\"june\"", June),
+            ("\"JULY\"", July),
+            ("\"august\"", August),
+            ("\"september\"", September),
+            ("\"October\"", October),
+            ("\"November\"", November),
+            ("\"DECEmbEr\"", December),
+        ];
+
+        for (string, expected_month) in cases {
+            let month = from_str::<Month>(string).unwrap();
+            assert_eq!(month, expected_month);
+        }
+
+        let errors: Vec<&str> =
+            vec!["\"not a month\"", "\"ja\"", "\"Dece\"", "Dec", "\"Augustin\""];
+
+        for string in errors {
+            from_str::<Month>(string).unwrap_err();
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Month;
+    use crate::{Datelike, TimeZone, Utc};
+
+    #[test]
+    fn test_month_enum_primitive_parse() {
+        use num_traits::FromPrimitive;
+
+        let jan_opt = Month::from_u32(1);
+        let feb_opt = Month::from_u64(2);
+        let dec_opt = Month::from_i64(12);
+        let no_month = Month::from_u32(13);
+        assert_eq!(jan_opt, Some(Month::January));
+        assert_eq!(feb_opt, Some(Month::February));
+        assert_eq!(dec_opt, Some(Month::December));
+        assert_eq!(no_month, None);
+
+        let date = Utc.with_ymd_and_hms(2019, 10, 28, 9, 10, 11).unwrap();
+        assert_eq!(Month::from_u32(date.month()), Some(Month::October));
+
+        let month = Month::January;
+        let dt = Utc.with_ymd_and_hms(2019, month.number_from_month(), 28, 9, 10, 11).unwrap();
+        assert_eq!((dt.year(), dt.month(), dt.day()), (2019, 1, 28));
+    }
+
+    #[test]
+    fn test_month_enum_succ_pred() {
+        assert_eq!(Month::January.succ(), Month::February);
+        assert_eq!(Month::December.succ(), Month::January);
+        assert_eq!(Month::January.pred(), Month::December);
+        assert_eq!(Month::February.pred(), Month::January);
+    }
+}

javascript-engine/external/chrono/src/naive/datetime/rustc_serialize.rs

@@ -0,0 +1,73 @@
+#![cfg_attr(docsrs, doc(cfg(feature = "rustc-serialize")))]
+
+use super::NaiveDateTime;
+use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
+use std::ops::Deref;
+
+impl Encodable for NaiveDateTime {
+    fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
+        format!("{:?}", self).encode(s)
+    }
+}
+
+impl Decodable for NaiveDateTime {
+    fn decode<D: Decoder>(d: &mut D) -> Result<NaiveDateTime, D::Error> {
+        d.read_str()?.parse().map_err(|_| d.error("invalid date time string"))
+    }
+}
+
+/// A `DateTime` that can be deserialized from a seconds-based timestamp
+#[derive(Debug)]
+#[deprecated(
+    since = "1.4.2",
+    note = "RustcSerialize will be removed before chrono 1.0, use Serde instead"
+)]
+pub struct TsSeconds(NaiveDateTime);
+
+#[allow(deprecated)]
+impl From<TsSeconds> for NaiveDateTime {
+    /// Pull the internal NaiveDateTime out
+    #[allow(deprecated)]
+    fn from(obj: TsSeconds) -> NaiveDateTime {
+        obj.0
+    }
+}
+
+#[allow(deprecated)]
+impl Deref for TsSeconds {
+    type Target = NaiveDateTime;
+
+    #[allow(deprecated)]
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[allow(deprecated)]
+impl Decodable for TsSeconds {
+    #[allow(deprecated)]
+    fn decode<D: Decoder>(d: &mut D) -> Result<TsSeconds, D::Error> {
+        Ok(TsSeconds(
+            NaiveDateTime::from_timestamp_opt(d.read_i64()?, 0)
+                .ok_or_else(|| d.error("invalid timestamp"))?,
+        ))
+    }
+}
+
+#[cfg(test)]
+use rustc_serialize::json;
+
+#[test]
+fn test_encodable() {
+    super::test_encodable_json(json::encode);
+}
+
+#[test]
+fn test_decodable() {
+    super::test_decodable_json(json::decode);
+}
+
+#[test]
+fn test_decodable_timestamps() {
+    super::test_decodable_json_timestamp(json::decode);
+}

javascript-engine/external/chrono/src/naive/datetime/tests.rs

@@ -0,0 +1,343 @@
+use super::NaiveDateTime;
+use crate::oldtime::Duration;
+use crate::NaiveDate;
+use crate::{Datelike, FixedOffset, Utc};
+use std::i64;
+
+#[test]
+fn test_datetime_from_timestamp_millis() {
+    let valid_map = [
+        (1662921288000, "2022-09-11 18:34:48.000000000"),
+        (1662921288123, "2022-09-11 18:34:48.123000000"),
+        (1662921287890, "2022-09-11 18:34:47.890000000"),
+        (-2208936075000, "1900-01-01 14:38:45.000000000"),
+        (0, "1970-01-01 00:00:00.000000000"),
+        (119731017000, "1973-10-17 18:36:57.000000000"),
+        (1234567890000, "2009-02-13 23:31:30.000000000"),
+        (2034061609000, "2034-06-16 09:06:49.000000000"),
+    ];
+
+    for (timestamp_millis, formatted) in valid_map.iter().copied() {
+        let naive_datetime = NaiveDateTime::from_timestamp_millis(timestamp_millis);
+        assert_eq!(timestamp_millis, naive_datetime.unwrap().timestamp_millis());
+        assert_eq!(naive_datetime.unwrap().format("%F %T%.9f").to_string(), formatted);
+    }
+
+    let invalid = [i64::MAX, i64::MIN];
+
+    for timestamp_millis in invalid.iter().copied() {
+        let naive_datetime = NaiveDateTime::from_timestamp_millis(timestamp_millis);
+        assert!(naive_datetime.is_none());
+    }
+
+    // Test that the result of `from_timestamp_millis` compares equal to
+    // that of `from_timestamp_opt`.
+    let secs_test = [0, 1, 2, 1000, 1234, 12345678, -1, -2, -1000, -12345678];
+    for secs in secs_test.iter().cloned() {
+        assert_eq!(
+            NaiveDateTime::from_timestamp_millis(secs * 1000),
+            NaiveDateTime::from_timestamp_opt(secs, 0)
+        );
+    }
+}
+
+#[test]
+fn test_datetime_from_timestamp_micros() {
+    let valid_map = [
+        (1662921288000000, "2022-09-11 18:34:48.000000000"),
+        (1662921288123456, "2022-09-11 18:34:48.123456000"),
+        (1662921287890000, "2022-09-11 18:34:47.890000000"),
+        (-2208936075000000, "1900-01-01 14:38:45.000000000"),
+        (0, "1970-01-01 00:00:00.000000000"),
+        (119731017000000, "1973-10-17 18:36:57.000000000"),
+        (1234567890000000, "2009-02-13 23:31:30.000000000"),
+        (2034061609000000, "2034-06-16 09:06:49.000000000"),
+    ];
+
+    for (timestamp_micros, formatted) in valid_map.iter().copied() {
+        let naive_datetime = NaiveDateTime::from_timestamp_micros(timestamp_micros);
+        assert_eq!(timestamp_micros, naive_datetime.unwrap().timestamp_micros());
+        assert_eq!(naive_datetime.unwrap().format("%F %T%.9f").to_string(), formatted);
+    }
+
+    let invalid = [i64::MAX, i64::MIN];
+
+    for timestamp_micros in invalid.iter().copied() {
+        let naive_datetime = NaiveDateTime::from_timestamp_micros(timestamp_micros);
+        assert!(naive_datetime.is_none());
+    }
+
+    // Test that the result of `from_timestamp_micros` compares equal to
+    // that of `from_timestamp_opt`.
+    let secs_test = [0, 1, 2, 1000, 1234, 12345678, -1, -2, -1000, -12345678];
+    for secs in secs_test.iter().copied() {
+        assert_eq!(
+            NaiveDateTime::from_timestamp_micros(secs * 1_000_000),
+            NaiveDateTime::from_timestamp_opt(secs, 0)
+        );
+    }
+}
+
+#[test]
+fn test_datetime_from_timestamp() {
+    let from_timestamp = |secs| NaiveDateTime::from_timestamp_opt(secs, 0);
+    let ymdhms =
+        |y, m, d, h, n, s| NaiveDate::from_ymd_opt(y, m, d).unwrap().and_hms_opt(h, n, s).unwrap();
+    assert_eq!(from_timestamp(-1), Some(ymdhms(1969, 12, 31, 23, 59, 59)));
+    assert_eq!(from_timestamp(0), Some(ymdhms(1970, 1, 1, 0, 0, 0)));
+    assert_eq!(from_timestamp(1), Some(ymdhms(1970, 1, 1, 0, 0, 1)));
+    assert_eq!(from_timestamp(1_000_000_000), Some(ymdhms(2001, 9, 9, 1, 46, 40)));
+    assert_eq!(from_timestamp(0x7fffffff), Some(ymdhms(2038, 1, 19, 3, 14, 7)));
+    assert_eq!(from_timestamp(i64::MIN), None);
+    assert_eq!(from_timestamp(i64::MAX), None);
+}
+
+#[test]
+fn test_datetime_add() {
+    fn check(
+        (y, m, d, h, n, s): (i32, u32, u32, u32, u32, u32),
+        rhs: Duration,
+        result: Option<(i32, u32, u32, u32, u32, u32)>,
+    ) {
+        let lhs = NaiveDate::from_ymd_opt(y, m, d).unwrap().and_hms_opt(h, n, s).unwrap();
+        let sum = result.map(|(y, m, d, h, n, s)| {
+            NaiveDate::from_ymd_opt(y, m, d).unwrap().and_hms_opt(h, n, s).unwrap()
+        });
+        assert_eq!(lhs.checked_add_signed(rhs), sum);
+        assert_eq!(lhs.checked_sub_signed(-rhs), sum);
+    }
+
+    check((2014, 5, 6, 7, 8, 9), Duration::seconds(3600 + 60 + 1), Some((2014, 5, 6, 8, 9, 10)));
+    check((2014, 5, 6, 7, 8, 9), Duration::seconds(-(3600 + 60 + 1)), Some((2014, 5, 6, 6, 7, 8)));
+    check((2014, 5, 6, 7, 8, 9), Duration::seconds(86399), Some((2014, 5, 7, 7, 8, 8)));
+    check((2014, 5, 6, 7, 8, 9), Duration::seconds(86_400 * 10), Some((2014, 5, 16, 7, 8, 9)));
+    check((2014, 5, 6, 7, 8, 9), Duration::seconds(-86_400 * 10), Some((2014, 4, 26, 7, 8, 9)));
+    check((2014, 5, 6, 7, 8, 9), Duration::seconds(86_400 * 10), Some((2014, 5, 16, 7, 8, 9)));
+
+    // overflow check
+    // assumes that we have correct values for MAX/MIN_DAYS_FROM_YEAR_0 from `naive::date`.
+    // (they are private constants, but the equivalence is tested in that module.)
+    let max_days_from_year_0 =
+        NaiveDate::MAX.signed_duration_since(NaiveDate::from_ymd_opt(0, 1, 1).unwrap());
+    check((0, 1, 1, 0, 0, 0), max_days_from_year_0, Some((NaiveDate::MAX.year(), 12, 31, 0, 0, 0)));
+    check(
+        (0, 1, 1, 0, 0, 0),
+        max_days_from_year_0 + Duration::seconds(86399),
+        Some((NaiveDate::MAX.year(), 12, 31, 23, 59, 59)),
+    );
+    check((0, 1, 1, 0, 0, 0), max_days_from_year_0 + Duration::seconds(86_400), None);
+    check((0, 1, 1, 0, 0, 0), Duration::max_value(), None);
+
+    let min_days_from_year_0 =
+        NaiveDate::MIN.signed_duration_since(NaiveDate::from_ymd_opt(0, 1, 1).unwrap());
+    check((0, 1, 1, 0, 0, 0), min_days_from_year_0, Some((NaiveDate::MIN.year(), 1, 1, 0, 0, 0)));
+    check((0, 1, 1, 0, 0, 0), min_days_from_year_0 - Duration::seconds(1), None);
+    check((0, 1, 1, 0, 0, 0), Duration::min_value(), None);
+}
+
+#[test]
+fn test_datetime_sub() {
+    let ymdhms =
+        |y, m, d, h, n, s| NaiveDate::from_ymd_opt(y, m, d).unwrap().and_hms_opt(h, n, s).unwrap();
+    let since = NaiveDateTime::signed_duration_since;
+    assert_eq!(since(ymdhms(2014, 5, 6, 7, 8, 9), ymdhms(2014, 5, 6, 7, 8, 9)), Duration::zero());
+    assert_eq!(
+        since(ymdhms(2014, 5, 6, 7, 8, 10), ymdhms(2014, 5, 6, 7, 8, 9)),
+        Duration::seconds(1)
+    );
+    assert_eq!(
+        since(ymdhms(2014, 5, 6, 7, 8, 9), ymdhms(2014, 5, 6, 7, 8, 10)),
+        Duration::seconds(-1)
+    );
+    assert_eq!(
+        since(ymdhms(2014, 5, 7, 7, 8, 9), ymdhms(2014, 5, 6, 7, 8, 10)),
+        Duration::seconds(86399)
+    );
+    assert_eq!(
+        since(ymdhms(2001, 9, 9, 1, 46, 39), ymdhms(1970, 1, 1, 0, 0, 0)),
+        Duration::seconds(999_999_999)
+    );
+}
+
+#[test]
+fn test_datetime_addassignment() {
+    let ymdhms =
+        |y, m, d, h, n, s| NaiveDate::from_ymd_opt(y, m, d).unwrap().and_hms_opt(h, n, s).unwrap();
+    let mut date = ymdhms(2016, 10, 1, 10, 10, 10);
+    date += Duration::minutes(10_000_000);
+    assert_eq!(date, ymdhms(2035, 10, 6, 20, 50, 10));
+    date += Duration::days(10);
+    assert_eq!(date, ymdhms(2035, 10, 16, 20, 50, 10));
+}
+
+#[test]
+fn test_datetime_subassignment() {
+    let ymdhms =
+        |y, m, d, h, n, s| NaiveDate::from_ymd_opt(y, m, d).unwrap().and_hms_opt(h, n, s).unwrap();
+    let mut date = ymdhms(2016, 10, 1, 10, 10, 10);
+    date -= Duration::minutes(10_000_000);
+    assert_eq!(date, ymdhms(1997, 9, 26, 23, 30, 10));
+    date -= Duration::days(10);
+    assert_eq!(date, ymdhms(1997, 9, 16, 23, 30, 10));
+}
+
+#[test]
+fn test_datetime_timestamp() {
+    let to_timestamp = |y, m, d, h, n, s| {
+        NaiveDate::from_ymd_opt(y, m, d).unwrap().and_hms_opt(h, n, s).unwrap().timestamp()
+    };
+    assert_eq!(to_timestamp(1969, 12, 31, 23, 59, 59), -1);
+    assert_eq!(to_timestamp(1970, 1, 1, 0, 0, 0), 0);
+    assert_eq!(to_timestamp(1970, 1, 1, 0, 0, 1), 1);
+    assert_eq!(to_timestamp(2001, 9, 9, 1, 46, 40), 1_000_000_000);
+    assert_eq!(to_timestamp(2038, 1, 19, 3, 14, 7), 0x7fffffff);
+}
+
+#[test]
+fn test_datetime_from_str() {
+    // valid cases
+    let valid = [
+        "2015-2-18T23:16:9.15",
+        "-77-02-18T23:16:09",
+        "  +82701  -  05  -  6  T  15  :  9  : 60.898989898989   ",
+    ];
+    for &s in &valid {
+        let d = match s.parse::<NaiveDateTime>() {
+            Ok(d) => d,
+            Err(e) => panic!("parsing `{}` has failed: {}", s, e),
+        };
+        let s_ = format!("{:?}", d);
+        // `s` and `s_` may differ, but `s.parse()` and `s_.parse()` must be same
+        let d_ = match s_.parse::<NaiveDateTime>() {
+            Ok(d) => d,
+            Err(e) => {
+                panic!("`{}` is parsed into `{:?}`, but reparsing that has failed: {}", s, d, e)
+            }
+        };
+        assert!(
+            d == d_,
+            "`{}` is parsed into `{:?}`, but reparsed result \
+             `{:?}` does not match",
+            s,
+            d,
+            d_
+        );
+    }
+
+    // some invalid cases
+    // since `ParseErrorKind` is private, all we can do is to check if there was an error
+    assert!("".parse::<NaiveDateTime>().is_err());
+    assert!("x".parse::<NaiveDateTime>().is_err());
+    assert!("15".parse::<NaiveDateTime>().is_err());
+    assert!("15:8:9".parse::<NaiveDateTime>().is_err());
+    assert!("15-8-9".parse::<NaiveDateTime>().is_err());
+    assert!("2015-15-15T15:15:15".parse::<NaiveDateTime>().is_err());
+    assert!("2012-12-12T12:12:12x".parse::<NaiveDateTime>().is_err());
+    assert!("2012-123-12T12:12:12".parse::<NaiveDateTime>().is_err());
+    assert!("+ 82701-123-12T12:12:12".parse::<NaiveDateTime>().is_err());
+    assert!("+802701-123-12T12:12:12".parse::<NaiveDateTime>().is_err()); // out-of-bound
+}
+
+#[test]
+fn test_datetime_parse_from_str() {
+    let ymdhms =
+        |y, m, d, h, n, s| NaiveDate::from_ymd_opt(y, m, d).unwrap().and_hms_opt(h, n, s).unwrap();
+    let ymdhmsn = |y, m, d, h, n, s, nano| {
+        NaiveDate::from_ymd_opt(y, m, d).unwrap().and_hms_nano_opt(h, n, s, nano).unwrap()
+    };
+    assert_eq!(
+        NaiveDateTime::parse_from_str("2014-5-7T12:34:56+09:30", "%Y-%m-%dT%H:%M:%S%z"),
+        Ok(ymdhms(2014, 5, 7, 12, 34, 56))
+    ); // ignore offset
+    assert_eq!(
+        NaiveDateTime::parse_from_str("2015-W06-1 000000", "%G-W%V-%u%H%M%S"),
+        Ok(ymdhms(2015, 2, 2, 0, 0, 0))
+    );
+    assert_eq!(
+        NaiveDateTime::parse_from_str("Fri, 09 Aug 2013 23:54:35 GMT", "%a, %d %b %Y %H:%M:%S GMT"),
+        Ok(ymdhms(2013, 8, 9, 23, 54, 35))
+    );
+    assert!(NaiveDateTime::parse_from_str(
+        "Sat, 09 Aug 2013 23:54:35 GMT",
+        "%a, %d %b %Y %H:%M:%S GMT"
+    )
+    .is_err());
+    assert!(NaiveDateTime::parse_from_str("2014-5-7 12:3456", "%Y-%m-%d %H:%M:%S").is_err());
+    assert!(NaiveDateTime::parse_from_str("12:34:56", "%H:%M:%S").is_err()); // insufficient
+    assert_eq!(
+        NaiveDateTime::parse_from_str("1441497364", "%s"),
+        Ok(ymdhms(2015, 9, 5, 23, 56, 4))
+    );
+    assert_eq!(
+        NaiveDateTime::parse_from_str("1283929614.1234", "%s.%f"),
+        Ok(ymdhmsn(2010, 9, 8, 7, 6, 54, 1234))
+    );
+    assert_eq!(
+        NaiveDateTime::parse_from_str("1441497364.649", "%s%.3f"),
+        Ok(ymdhmsn(2015, 9, 5, 23, 56, 4, 649000000))
+    );
+    assert_eq!(
+        NaiveDateTime::parse_from_str("1497854303.087654", "%s%.6f"),
+        Ok(ymdhmsn(2017, 6, 19, 6, 38, 23, 87654000))
+    );
+    assert_eq!(
+        NaiveDateTime::parse_from_str("1437742189.918273645", "%s%.9f"),
+        Ok(ymdhmsn(2015, 7, 24, 12, 49, 49, 918273645))
+    );
+}
+
+#[test]
+fn test_datetime_format() {
+    let dt = NaiveDate::from_ymd_opt(2010, 9, 8).unwrap().and_hms_milli_opt(7, 6, 54, 321).unwrap();
+    assert_eq!(dt.format("%c").to_string(), "Wed Sep  8 07:06:54 2010");
+    assert_eq!(dt.format("%s").to_string(), "1283929614");
+    assert_eq!(dt.format("%t%n%%%n%t").to_string(), "\t\n%\n\t");
+
+    // a horror of leap second: coming near to you.
+    let dt =
+        NaiveDate::from_ymd_opt(2012, 6, 30).unwrap().and_hms_milli_opt(23, 59, 59, 1_000).unwrap();
+    assert_eq!(dt.format("%c").to_string(), "Sat Jun 30 23:59:60 2012");
+    assert_eq!(dt.format("%s").to_string(), "1341100799"); // not 1341100800, it's intentional.
+}
+
+#[test]
+fn test_datetime_add_sub_invariant() {
+    // issue #37
+    let base = NaiveDate::from_ymd_opt(2000, 1, 1).unwrap().and_hms_opt(0, 0, 0).unwrap();
+    let t = -946684799990000;
+    let time = base + Duration::microseconds(t);
+    assert_eq!(t, time.signed_duration_since(base).num_microseconds().unwrap());
+}
+
+#[test]
+fn test_nanosecond_range() {
+    const A_BILLION: i64 = 1_000_000_000;
+    let maximum = "2262-04-11T23:47:16.854775804";
+    let parsed: NaiveDateTime = maximum.parse().unwrap();
+    let nanos = parsed.timestamp_nanos();
+    assert_eq!(
+        parsed,
+        NaiveDateTime::from_timestamp_opt(nanos / A_BILLION, (nanos % A_BILLION) as u32).unwrap()
+    );
+
+    let minimum = "1677-09-21T00:12:44.000000000";
+    let parsed: NaiveDateTime = minimum.parse().unwrap();
+    let nanos = parsed.timestamp_nanos();
+    assert_eq!(
+        parsed,
+        NaiveDateTime::from_timestamp_opt(nanos / A_BILLION, (nanos % A_BILLION) as u32).unwrap()
+    );
+}
+
+#[test]
+fn test_and_timezone() {
+    let ndt = NaiveDate::from_ymd_opt(2022, 6, 15).unwrap().and_hms_opt(18, 59, 36).unwrap();
+    let dt_utc = ndt.and_local_timezone(Utc).unwrap();
+    assert_eq!(dt_utc.naive_local(), ndt);
+    assert_eq!(dt_utc.timezone(), Utc);
+
+    let offset_tz = FixedOffset::west_opt(4 * 3600).unwrap();
+    let dt_offset = ndt.and_local_timezone(offset_tz).unwrap();
+    assert_eq!(dt_offset.naive_local(), ndt);
+    assert_eq!(dt_offset.timezone(), offset_tz);
+}

javascript-engine/external/chrono/src/naive/internals.rs

@@ -0,0 +1,816 @@
+// This is a part of Chrono.
+// See README.md and LICENSE.txt for details.
+
+//! The internal implementation of the calendar and ordinal date.
+//!
+//! The current implementation is optimized for determining year, month, day and day of week.
+//! 4-bit `YearFlags` map to one of 14 possible classes of year in the Gregorian calendar,
+//! which are included in every packed `NaiveDate` instance.
+//! The conversion between the packed calendar date (`Mdf`) and the ordinal date (`Of`) is
+//! based on the moderately-sized lookup table (~1.5KB)
+//! and the packed representation is chosen for the efficient lookup.
+//! Every internal data structure does not validate its input,
+//! but the conversion keeps the valid value valid and the invalid value invalid
+//! so that the user-facing `NaiveDate` can validate the input as late as possible.
+
+#![cfg_attr(feature = "__internal_bench", allow(missing_docs))]
+
+use crate::Weekday;
+use core::{fmt, i32};
+use num_integer::{div_rem, mod_floor};
+use num_traits::FromPrimitive;
+
+/// The internal date representation. This also includes the packed `Mdf` value.
+pub(super) type DateImpl = i32;
+
+pub(super) const MAX_YEAR: DateImpl = i32::MAX >> 13;
+pub(super) const MIN_YEAR: DateImpl = i32::MIN >> 13;
+
+/// The year flags (aka the dominical letter).
+///
+/// There are 14 possible classes of year in the Gregorian calendar:
+/// common and leap years starting with Monday through Sunday.
+/// The `YearFlags` stores this information into 4 bits `abbb`,
+/// where `a` is `1` for the common year (simplifies the `Of` validation)
+/// and `bbb` is a non-zero `Weekday` (mapping `Mon` to 7) of the last day in the past year
+/// (simplifies the day of week calculation from the 1-based ordinal).
+#[allow(unreachable_pub)] // public as an alias for benchmarks only
+#[derive(PartialEq, Eq, Copy, Clone)]
+pub struct YearFlags(pub(super) u8);
+
+pub(super) const A: YearFlags = YearFlags(0o15);
+pub(super) const AG: YearFlags = YearFlags(0o05);
+pub(super) const B: YearFlags = YearFlags(0o14);
+pub(super) const BA: YearFlags = YearFlags(0o04);
+pub(super) const C: YearFlags = YearFlags(0o13);
+pub(super) const CB: YearFlags = YearFlags(0o03);
+pub(super) const D: YearFlags = YearFlags(0o12);
+pub(super) const DC: YearFlags = YearFlags(0o02);
+pub(super) const E: YearFlags = YearFlags(0o11);
+pub(super) const ED: YearFlags = YearFlags(0o01);
+pub(super) const F: YearFlags = YearFlags(0o17);
+pub(super) const FE: YearFlags = YearFlags(0o07);
+pub(super) const G: YearFlags = YearFlags(0o16);
+pub(super) const GF: YearFlags = YearFlags(0o06);
+
+static YEAR_TO_FLAGS: [YearFlags; 400] = [
+    BA, G, F, E, DC, B, A, G, FE, D, C, B, AG, F, E, D, CB, A, G, F, ED, C, B, A, GF, E, D, C, BA,
+    G, F, E, DC, B, A, G, FE, D, C, B, AG, F, E, D, CB, A, G, F, ED, C, B, A, GF, E, D, C, BA, G,
+    F, E, DC, B, A, G, FE, D, C, B, AG, F, E, D, CB, A, G, F, ED, C, B, A, GF, E, D, C, BA, G, F,
+    E, DC, B, A, G, FE, D, C, B, AG, F, E, D, // 100
+    C, B, A, G, FE, D, C, B, AG, F, E, D, CB, A, G, F, ED, C, B, A, GF, E, D, C, BA, G, F, E, DC,
+    B, A, G, FE, D, C, B, AG, F, E, D, CB, A, G, F, ED, C, B, A, GF, E, D, C, BA, G, F, E, DC, B,
+    A, G, FE, D, C, B, AG, F, E, D, CB, A, G, F, ED, C, B, A, GF, E, D, C, BA, G, F, E, DC, B, A,
+    G, FE, D, C, B, AG, F, E, D, CB, A, G, F, // 200
+    E, D, C, B, AG, F, E, D, CB, A, G, F, ED, C, B, A, GF, E, D, C, BA, G, F, E, DC, B, A, G, FE,
+    D, C, B, AG, F, E, D, CB, A, G, F, ED, C, B, A, GF, E, D, C, BA, G, F, E, DC, B, A, G, FE, D,
+    C, B, AG, F, E, D, CB, A, G, F, ED, C, B, A, GF, E, D, C, BA, G, F, E, DC, B, A, G, FE, D, C,
+    B, AG, F, E, D, CB, A, G, F, ED, C, B, A, // 300
+    G, F, E, D, CB, A, G, F, ED, C, B, A, GF, E, D, C, BA, G, F, E, DC, B, A, G, FE, D, C, B, AG,
+    F, E, D, CB, A, G, F, ED, C, B, A, GF, E, D, C, BA, G, F, E, DC, B, A, G, FE, D, C, B, AG, F,
+    E, D, CB, A, G, F, ED, C, B, A, GF, E, D, C, BA, G, F, E, DC, B, A, G, FE, D, C, B, AG, F, E,
+    D, CB, A, G, F, ED, C, B, A, GF, E, D, C, // 400
+];
+
+static YEAR_DELTAS: [u8; 401] = [
+    0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8,
+    8, 9, 9, 9, 9, 10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12, 13, 13, 13, 13, 14, 14, 14, 14,
+    15, 15, 15, 15, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18, 19, 19, 19, 19, 20, 20, 20, 20,
+    21, 21, 21, 21, 22, 22, 22, 22, 23, 23, 23, 23, 24, 24, 24, 24, 25, 25, 25, // 100
+    25, 25, 25, 25, 25, 26, 26, 26, 26, 27, 27, 27, 27, 28, 28, 28, 28, 29, 29, 29, 29, 30, 30, 30,
+    30, 31, 31, 31, 31, 32, 32, 32, 32, 33, 33, 33, 33, 34, 34, 34, 34, 35, 35, 35, 35, 36, 36, 36,
+    36, 37, 37, 37, 37, 38, 38, 38, 38, 39, 39, 39, 39, 40, 40, 40, 40, 41, 41, 41, 41, 42, 42, 42,
+    42, 43, 43, 43, 43, 44, 44, 44, 44, 45, 45, 45, 45, 46, 46, 46, 46, 47, 47, 47, 47, 48, 48, 48,
+    48, 49, 49, 49, // 200
+    49, 49, 49, 49, 49, 50, 50, 50, 50, 51, 51, 51, 51, 52, 52, 52, 52, 53, 53, 53, 53, 54, 54, 54,
+    54, 55, 55, 55, 55, 56, 56, 56, 56, 57, 57, 57, 57, 58, 58, 58, 58, 59, 59, 59, 59, 60, 60, 60,
+    60, 61, 61, 61, 61, 62, 62, 62, 62, 63, 63, 63, 63, 64, 64, 64, 64, 65, 65, 65, 65, 66, 66, 66,
+    66, 67, 67, 67, 67, 68, 68, 68, 68, 69, 69, 69, 69, 70, 70, 70, 70, 71, 71, 71, 71, 72, 72, 72,
+    72, 73, 73, 73, // 300
+    73, 73, 73, 73, 73, 74, 74, 74, 74, 75, 75, 75, 75, 76, 76, 76, 76, 77, 77, 77, 77, 78, 78, 78,
+    78, 79, 79, 79, 79, 80, 80, 80, 80, 81, 81, 81, 81, 82, 82, 82, 82, 83, 83, 83, 83, 84, 84, 84,
+    84, 85, 85, 85, 85, 86, 86, 86, 86, 87, 87, 87, 87, 88, 88, 88, 88, 89, 89, 89, 89, 90, 90, 90,
+    90, 91, 91, 91, 91, 92, 92, 92, 92, 93, 93, 93, 93, 94, 94, 94, 94, 95, 95, 95, 95, 96, 96, 96,
+    96, 97, 97, 97, 97, // 400+1
+];
+
+pub(super) fn cycle_to_yo(cycle: u32) -> (u32, u32) {
+    let (mut year_mod_400, mut ordinal0) = div_rem(cycle, 365);
+    let delta = u32::from(YEAR_DELTAS[year_mod_400 as usize]);
+    if ordinal0 < delta {
+        year_mod_400 -= 1;
+        ordinal0 += 365 - u32::from(YEAR_DELTAS[year_mod_400 as usize]);
+    } else {
+        ordinal0 -= delta;
+    }
+    (year_mod_400, ordinal0 + 1)
+}
+
+pub(super) fn yo_to_cycle(year_mod_400: u32, ordinal: u32) -> u32 {
+    year_mod_400 * 365 + u32::from(YEAR_DELTAS[year_mod_400 as usize]) + ordinal - 1
+}
+
+impl YearFlags {
+    #[allow(unreachable_pub)] // public as an alias for benchmarks only
+    #[doc(hidden)] // for benchmarks only
+    #[inline]
+    pub fn from_year(year: i32) -> YearFlags {
+        let year = mod_floor(year, 400);
+        YearFlags::from_year_mod_400(year)
+    }
+
+    #[inline]
+    pub(super) fn from_year_mod_400(year: i32) -> YearFlags {
+        YEAR_TO_FLAGS[year as usize]
+    }
+
+    #[inline]
+    pub(super) fn ndays(&self) -> u32 {
+        let YearFlags(flags) = *self;
+        366 - u32::from(flags >> 3)
+    }
+
+    #[inline]
+    pub(super) fn isoweek_delta(&self) -> u32 {
+        let YearFlags(flags) = *self;
+        let mut delta = u32::from(flags) & 0b0111;
+        if delta < 3 {
+            delta += 7;
+        }
+        delta
+    }
+
+    #[inline]
+    pub(super) fn nisoweeks(&self) -> u32 {
+        let YearFlags(flags) = *self;
+        52 + ((0b0000_0100_0000_0110 >> flags as usize) & 1)
+    }
+}
+
+impl fmt::Debug for YearFlags {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let YearFlags(flags) = *self;
+        match flags {
+            0o15 => "A".fmt(f),
+            0o05 => "AG".fmt(f),
+            0o14 => "B".fmt(f),
+            0o04 => "BA".fmt(f),
+            0o13 => "C".fmt(f),
+            0o03 => "CB".fmt(f),
+            0o12 => "D".fmt(f),
+            0o02 => "DC".fmt(f),
+            0o11 => "E".fmt(f),
+            0o01 => "ED".fmt(f),
+            0o10 => "F?".fmt(f),
+            0o00 => "FE?".fmt(f), // non-canonical
+            0o17 => "F".fmt(f),
+            0o07 => "FE".fmt(f),
+            0o16 => "G".fmt(f),
+            0o06 => "GF".fmt(f),
+            _ => write!(f, "YearFlags({})", flags),
+        }
+    }
+}
+
+pub(super) const MIN_OL: u32 = 1 << 1;
+pub(super) const MAX_OL: u32 = 366 << 1; // larger than the non-leap last day `(365 << 1) | 1`
+pub(super) const MAX_MDL: u32 = (12 << 6) | (31 << 1) | 1;
+
+const XX: i8 = -128;
+static MDL_TO_OL: [i8; MAX_MDL as usize + 1] = [
+    XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX,
+    XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX,
+    XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, // 0
+    XX, XX, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, // 1
+    XX, XX, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66,
+    66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66,
+    66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, XX, XX, XX, XX, XX, // 2
+    XX, XX, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74,
+    72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74,
+    72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, // 3
+    XX, XX, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76,
+    74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76,
+    74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, XX, XX, // 4
+    XX, XX, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80,
+    78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80,
+    78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, // 5
+    XX, XX, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82,
+    80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82,
+    80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, XX, XX, // 6
+    XX, XX, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86,
+    84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86,
+    84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, // 7
+    XX, XX, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88,
+    86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88,
+    86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, // 8
+    XX, XX, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90,
+    88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90,
+    88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, XX, XX, // 9
+    XX, XX, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94,
+    92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94,
+    92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, // 10
+    XX, XX, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96,
+    94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96,
+    94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, XX, XX, // 11
+    XX, XX, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98,
+    100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100,
+    98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98,
+    100, // 12
+];
+
+static OL_TO_MDL: [u8; MAX_OL as usize + 1] = [
+    0, 0, // 0
+    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, // 1
+    66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66,
+    66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66,
+    66, 66, 66, 66, 66, 66, 66, 66, 66, // 2
+    74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72,
+    74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72,
+    74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, 74, 72, // 3
+    76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74,
+    76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74,
+    76, 74, 76, 74, 76, 74, 76, 74, 76, 74, 76, 74, // 4
+    80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78,
+    80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78,
+    80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, 80, 78, // 5
+    82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80,
+    82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80,
+    82, 80, 82, 80, 82, 80, 82, 80, 82, 80, 82, 80, // 6
+    86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84,
+    86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84,
+    86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, 86, 84, // 7
+    88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86,
+    88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86,
+    88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, 88, 86, // 8
+    90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88,
+    90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88,
+    90, 88, 90, 88, 90, 88, 90, 88, 90, 88, 90, 88, // 9
+    94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92,
+    94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92,
+    94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, 94, 92, // 10
+    96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94,
+    96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94,
+    96, 94, 96, 94, 96, 94, 96, 94, 96, 94, 96, 94, // 11
+    100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100,
+    98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98,
+    100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100, 98, 100,
+    98, // 12
+];
+
+/// Ordinal (day of year) and year flags: `(ordinal << 4) | flags`.
+///
+/// The whole bits except for the least 3 bits are referred as `Ol` (ordinal and leap flag),
+/// which is an index to the `OL_TO_MDL` lookup table.
+#[derive(PartialEq, PartialOrd, Copy, Clone)]
+pub(super) struct Of(pub(crate) u32);
+
+impl Of {
+    #[inline]
+    pub(super) fn new(ordinal: u32, YearFlags(flags): YearFlags) -> Option<Of> {
+        match ordinal <= 366 {
+            true => Some(Of((ordinal << 4) | u32::from(flags))),
+            false => None,
+        }
+    }
+
+    #[inline]
+    pub(super) fn from_mdf(Mdf(mdf): Mdf) -> Of {
+        let mdl = mdf >> 3;
+        match MDL_TO_OL.get(mdl as usize) {
+            Some(&v) => Of(mdf.wrapping_sub((i32::from(v) as u32 & 0x3ff) << 3)),
+            None => Of(0),
+        }
+    }
+
+    #[inline]
+    pub(super) fn valid(&self) -> bool {
+        let Of(of) = *self;
+        let ol = of >> 3;
+        (MIN_OL..=MAX_OL).contains(&ol)
+    }
+
+    #[inline]
+    pub(super) fn ordinal(&self) -> u32 {
+        let Of(of) = *self;
+        of >> 4
+    }
+
+    #[inline]
+    pub(super) fn with_ordinal(&self, ordinal: u32) -> Option<Of> {
+        if ordinal > 366 {
+            return None;
+        }
+
+        let Of(of) = *self;
+        Some(Of((of & 0b1111) | (ordinal << 4)))
+    }
+
+    #[inline]
+    pub(super) fn flags(&self) -> YearFlags {
+        let Of(of) = *self;
+        YearFlags((of & 0b1111) as u8)
+    }
+
+    #[inline]
+    pub(super) fn weekday(&self) -> Weekday {
+        let Of(of) = *self;
+        Weekday::from_u32(((of >> 4) + (of & 0b111)) % 7).unwrap()
+    }
+
+    #[inline]
+    pub(super) fn isoweekdate_raw(&self) -> (u32, Weekday) {
+        // week ordinal = ordinal + delta
+        let Of(of) = *self;
+        let weekord = (of >> 4).wrapping_add(self.flags().isoweek_delta());
+        (weekord / 7, Weekday::from_u32(weekord % 7).unwrap())
+    }
+
+    #[cfg_attr(feature = "cargo-clippy", allow(clippy::wrong_self_convention))]
+    #[inline]
+    pub(super) fn to_mdf(&self) -> Mdf {
+        Mdf::from_of(*self)
+    }
+
+    #[inline]
+    pub(super) fn succ(&self) -> Of {
+        let Of(of) = *self;
+        Of(of + (1 << 4))
+    }
+
+    #[inline]
+    pub(super) fn pred(&self) -> Of {
+        let Of(of) = *self;
+        Of(of - (1 << 4))
+    }
+}
+
+impl fmt::Debug for Of {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let Of(of) = *self;
+        write!(
+            f,
+            "Of(({} << 4) | {:#04o} /*{:?}*/)",
+            of >> 4,
+            of & 0b1111,
+            YearFlags((of & 0b1111) as u8)
+        )
+    }
+}
+
+/// Month, day of month and year flags: `(month << 9) | (day << 4) | flags`
+///
+/// The whole bits except for the least 3 bits are referred as `Mdl`
+/// (month, day of month and leap flag),
+/// which is an index to the `MDL_TO_OL` lookup table.
+#[derive(PartialEq, PartialOrd, Copy, Clone)]
+pub(super) struct Mdf(pub(super) u32);
+
+impl Mdf {
+    #[inline]
+    pub(super) fn new(month: u32, day: u32, YearFlags(flags): YearFlags) -> Option<Mdf> {
+        match month <= 12 && day <= 31 {
+            true => Some(Mdf((month << 9) | (day << 4) | u32::from(flags))),
+            false => None,
+        }
+    }
+
+    #[inline]
+    pub(super) fn from_of(Of(of): Of) -> Mdf {
+        let ol = of >> 3;
+        match OL_TO_MDL.get(ol as usize) {
+            Some(&v) => Mdf(of + (u32::from(v) << 3)),
+            None => Mdf(0),
+        }
+    }
+
+    #[cfg(test)]
+    pub(super) fn valid(&self) -> bool {
+        let Mdf(mdf) = *self;
+        let mdl = mdf >> 3;
+        match MDL_TO_OL.get(mdl as usize) {
+            Some(&v) => v >= 0,
+            None => false,
+        }
+    }
+
+    #[inline]
+    pub(super) fn month(&self) -> u32 {
+        let Mdf(mdf) = *self;
+        mdf >> 9
+    }
+
+    #[inline]
+    pub(super) fn with_month(&self, month: u32) -> Option<Mdf> {
+        if month > 12 {
+            return None;
+        }
+
+        let Mdf(mdf) = *self;
+        Some(Mdf((mdf & 0b1_1111_1111) | (month << 9)))
+    }
+
+    #[inline]
+    pub(super) fn day(&self) -> u32 {
+        let Mdf(mdf) = *self;
+        (mdf >> 4) & 0b1_1111
+    }
+
+    #[inline]
+    pub(super) fn with_day(&self, day: u32) -> Option<Mdf> {
+        if day > 31 {
+            return None;
+        }
+
+        let Mdf(mdf) = *self;
+        Some(Mdf((mdf & !0b1_1111_0000) | (day << 4)))
+    }
+
+    #[inline]
+    pub(super) fn with_flags(&self, YearFlags(flags): YearFlags) -> Mdf {
+        let Mdf(mdf) = *self;
+        Mdf((mdf & !0b1111) | u32::from(flags))
+    }
+
+    #[cfg_attr(feature = "cargo-clippy", allow(clippy::wrong_self_convention))]
+    #[inline]
+    pub(super) fn to_of(&self) -> Of {
+        Of::from_mdf(*self)
+    }
+}
+
+impl fmt::Debug for Mdf {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let Mdf(mdf) = *self;
+        write!(
+            f,
+            "Mdf(({} << 9) | ({} << 4) | {:#04o} /*{:?}*/)",
+            mdf >> 9,
+            (mdf >> 4) & 0b1_1111,
+            mdf & 0b1111,
+            YearFlags((mdf & 0b1111) as u8)
+        )
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use num_iter::range_inclusive;
+    use std::u32;
+
+    use super::{Mdf, Of};
+    use super::{YearFlags, A, AG, B, BA, C, CB, D, DC, E, ED, F, FE, G, GF};
+    use crate::Weekday;
+
+    const NONLEAP_FLAGS: [YearFlags; 7] = [A, B, C, D, E, F, G];
+    const LEAP_FLAGS: [YearFlags; 7] = [AG, BA, CB, DC, ED, FE, GF];
+    const FLAGS: [YearFlags; 14] = [A, B, C, D, E, F, G, AG, BA, CB, DC, ED, FE, GF];
+
+    #[test]
+    fn test_year_flags_ndays_from_year() {
+        assert_eq!(YearFlags::from_year(2014).ndays(), 365);
+        assert_eq!(YearFlags::from_year(2012).ndays(), 366);
+        assert_eq!(YearFlags::from_year(2000).ndays(), 366);
+        assert_eq!(YearFlags::from_year(1900).ndays(), 365);
+        assert_eq!(YearFlags::from_year(1600).ndays(), 366);
+        assert_eq!(YearFlags::from_year(1).ndays(), 365);
+        assert_eq!(YearFlags::from_year(0).ndays(), 366); // 1 BCE (proleptic Gregorian)
+        assert_eq!(YearFlags::from_year(-1).ndays(), 365); // 2 BCE
+        assert_eq!(YearFlags::from_year(-4).ndays(), 366); // 5 BCE
+        assert_eq!(YearFlags::from_year(-99).ndays(), 365); // 100 BCE
+        assert_eq!(YearFlags::from_year(-100).ndays(), 365); // 101 BCE
+        assert_eq!(YearFlags::from_year(-399).ndays(), 365); // 400 BCE
+        assert_eq!(YearFlags::from_year(-400).ndays(), 366); // 401 BCE
+    }
+
+    #[test]
+    fn test_year_flags_nisoweeks() {
+        assert_eq!(A.nisoweeks(), 52);
+        assert_eq!(B.nisoweeks(), 52);
+        assert_eq!(C.nisoweeks(), 52);
+        assert_eq!(D.nisoweeks(), 53);
+        assert_eq!(E.nisoweeks(), 52);
+        assert_eq!(F.nisoweeks(), 52);
+        assert_eq!(G.nisoweeks(), 52);
+        assert_eq!(AG.nisoweeks(), 52);
+        assert_eq!(BA.nisoweeks(), 52);
+        assert_eq!(CB.nisoweeks(), 52);
+        assert_eq!(DC.nisoweeks(), 53);
+        assert_eq!(ED.nisoweeks(), 53);
+        assert_eq!(FE.nisoweeks(), 52);
+        assert_eq!(GF.nisoweeks(), 52);
+    }
+
+    #[test]
+    fn test_of() {
+        fn check(expected: bool, flags: YearFlags, ordinal1: u32, ordinal2: u32) {
+            for ordinal in range_inclusive(ordinal1, ordinal2) {
+                let of = match Of::new(ordinal, flags) {
+                    Some(of) => of,
+                    None if !expected => continue,
+                    None => panic!("Of::new({}, {:?}) returned None", ordinal, flags),
+                };
+
+                assert!(
+                    of.valid() == expected,
+                    "ordinal {} = {:?} should be {} for dominical year {:?}",
+                    ordinal,
+                    of,
+                    if expected { "valid" } else { "invalid" },
+                    flags
+                );
+            }
+        }
+
+        for &flags in NONLEAP_FLAGS.iter() {
+            check(false, flags, 0, 0);
+            check(true, flags, 1, 365);
+            check(false, flags, 366, 1024);
+            check(false, flags, u32::MAX, u32::MAX);
+        }
+
+        for &flags in LEAP_FLAGS.iter() {
+            check(false, flags, 0, 0);
+            check(true, flags, 1, 366);
+            check(false, flags, 367, 1024);
+            check(false, flags, u32::MAX, u32::MAX);
+        }
+    }
+
+    #[test]
+    fn test_mdf_valid() {
+        fn check(expected: bool, flags: YearFlags, month1: u32, day1: u32, month2: u32, day2: u32) {
+            for month in range_inclusive(month1, month2) {
+                for day in range_inclusive(day1, day2) {
+                    let mdf = match Mdf::new(month, day, flags) {
+                        Some(mdf) => mdf,
+                        None if !expected => continue,
+                        None => panic!("Mdf::new({}, {}, {:?}) returned None", month, day, flags),
+                    };
+
+                    assert!(
+                        mdf.valid() == expected,
+                        "month {} day {} = {:?} should be {} for dominical year {:?}",
+                        month,
+                        day,
+                        mdf,
+                        if expected { "valid" } else { "invalid" },
+                        flags
+                    );
+                }
+            }
+        }
+
+        for &flags in NONLEAP_FLAGS.iter() {
+            check(false, flags, 0, 0, 0, 1024);
+            check(false, flags, 0, 0, 16, 0);
+            check(true, flags, 1, 1, 1, 31);
+            check(false, flags, 1, 32, 1, 1024);
+            check(true, flags, 2, 1, 2, 28);
+            check(false, flags, 2, 29, 2, 1024);
+            check(true, flags, 3, 1, 3, 31);
+            check(false, flags, 3, 32, 3, 1024);
+            check(true, flags, 4, 1, 4, 30);
+            check(false, flags, 4, 31, 4, 1024);
+            check(true, flags, 5, 1, 5, 31);
+            check(false, flags, 5, 32, 5, 1024);
+            check(true, flags, 6, 1, 6, 30);
+            check(false, flags, 6, 31, 6, 1024);
+            check(true, flags, 7, 1, 7, 31);
+            check(false, flags, 7, 32, 7, 1024);
+            check(true, flags, 8, 1, 8, 31);
+            check(false, flags, 8, 32, 8, 1024);
+            check(true, flags, 9, 1, 9, 30);
+            check(false, flags, 9, 31, 9, 1024);
+            check(true, flags, 10, 1, 10, 31);
+            check(false, flags, 10, 32, 10, 1024);
+            check(true, flags, 11, 1, 11, 30);
+            check(false, flags, 11, 31, 11, 1024);
+            check(true, flags, 12, 1, 12, 31);
+            check(false, flags, 12, 32, 12, 1024);
+            check(false, flags, 13, 0, 16, 1024);
+            check(false, flags, u32::MAX, 0, u32::MAX, 1024);
+            check(false, flags, 0, u32::MAX, 16, u32::MAX);
+            check(false, flags, u32::MAX, u32::MAX, u32::MAX, u32::MAX);
+        }
+
+        for &flags in LEAP_FLAGS.iter() {
+            check(false, flags, 0, 0, 0, 1024);
+            check(false, flags, 0, 0, 16, 0);
+            check(true, flags, 1, 1, 1, 31);
+            check(false, flags, 1, 32, 1, 1024);
+            check(true, flags, 2, 1, 2, 29);
+            check(false, flags, 2, 30, 2, 1024);
+            check(true, flags, 3, 1, 3, 31);
+            check(false, flags, 3, 32, 3, 1024);
+            check(true, flags, 4, 1, 4, 30);
+            check(false, flags, 4, 31, 4, 1024);
+            check(true, flags, 5, 1, 5, 31);
+            check(false, flags, 5, 32, 5, 1024);
+            check(true, flags, 6, 1, 6, 30);
+            check(false, flags, 6, 31, 6, 1024);
+            check(true, flags, 7, 1, 7, 31);
+            check(false, flags, 7, 32, 7, 1024);
+            check(true, flags, 8, 1, 8, 31);
+            check(false, flags, 8, 32, 8, 1024);
+            check(true, flags, 9, 1, 9, 30);
+            check(false, flags, 9, 31, 9, 1024);
+            check(true, flags, 10, 1, 10, 31);
+            check(false, flags, 10, 32, 10, 1024);
+            check(true, flags, 11, 1, 11, 30);
+            check(false, flags, 11, 31, 11, 1024);
+            check(true, flags, 12, 1, 12, 31);
+            check(false, flags, 12, 32, 12, 1024);
+            check(false, flags, 13, 0, 16, 1024);
+            check(false, flags, u32::MAX, 0, u32::MAX, 1024);
+            check(false, flags, 0, u32::MAX, 16, u32::MAX);
+            check(false, flags, u32::MAX, u32::MAX, u32::MAX, u32::MAX);
+        }
+    }
+
+    #[test]
+    fn test_of_fields() {
+        for &flags in FLAGS.iter() {
+            for ordinal in range_inclusive(1u32, 366) {
+                let of = Of::new(ordinal, flags).unwrap();
+                if of.valid() {
+                    assert_eq!(of.ordinal(), ordinal);
+                }
+            }
+        }
+    }
+
+    #[test]
+    fn test_of_with_fields() {
+        fn check(flags: YearFlags, ordinal: u32) {
+            let of = Of::new(ordinal, flags).unwrap();
+
+            for ordinal in range_inclusive(0u32, 1024) {
+                let of = match of.with_ordinal(ordinal) {
+                    Some(of) => of,
+                    None if ordinal > 366 => continue,
+                    None => panic!("failed to create Of with ordinal {}", ordinal),
+                };
+
+                assert_eq!(of.valid(), Of::new(ordinal, flags).unwrap().valid());
+                if of.valid() {
+                    assert_eq!(of.ordinal(), ordinal);
+                }
+            }
+        }
+
+        for &flags in NONLEAP_FLAGS.iter() {
+            check(flags, 1);
+            check(flags, 365);
+        }
+        for &flags in LEAP_FLAGS.iter() {
+            check(flags, 1);
+            check(flags, 366);
+        }
+    }
+
+    #[test]
+    fn test_of_weekday() {
+        assert_eq!(Of::new(1, A).unwrap().weekday(), Weekday::Sun);
+        assert_eq!(Of::new(1, B).unwrap().weekday(), Weekday::Sat);
+        assert_eq!(Of::new(1, C).unwrap().weekday(), Weekday::Fri);
+        assert_eq!(Of::new(1, D).unwrap().weekday(), Weekday::Thu);
+        assert_eq!(Of::new(1, E).unwrap().weekday(), Weekday::Wed);
+        assert_eq!(Of::new(1, F).unwrap().weekday(), Weekday::Tue);
+        assert_eq!(Of::new(1, G).unwrap().weekday(), Weekday::Mon);
+        assert_eq!(Of::new(1, AG).unwrap().weekday(), Weekday::Sun);
+        assert_eq!(Of::new(1, BA).unwrap().weekday(), Weekday::Sat);
+        assert_eq!(Of::new(1, CB).unwrap().weekday(), Weekday::Fri);
+        assert_eq!(Of::new(1, DC).unwrap().weekday(), Weekday::Thu);
+        assert_eq!(Of::new(1, ED).unwrap().weekday(), Weekday::Wed);
+        assert_eq!(Of::new(1, FE).unwrap().weekday(), Weekday::Tue);
+        assert_eq!(Of::new(1, GF).unwrap().weekday(), Weekday::Mon);
+
+        for &flags in FLAGS.iter() {
+            let mut prev = Of::new(1, flags).unwrap().weekday();
+            for ordinal in range_inclusive(2u32, flags.ndays()) {
+                let of = Of::new(ordinal, flags).unwrap();
+                let expected = prev.succ();
+                assert_eq!(of.weekday(), expected);
+                prev = expected;
+            }
+        }
+    }
+
+    #[test]
+    fn test_mdf_fields() {
+        for &flags in FLAGS.iter() {
+            for month in range_inclusive(1u32, 12) {
+                for day in range_inclusive(1u32, 31) {
+                    let mdf = match Mdf::new(month, day, flags) {
+                        Some(mdf) => mdf,
+                        None => continue,
+                    };
+
+                    if mdf.valid() {
+                        assert_eq!(mdf.month(), month);
+                        assert_eq!(mdf.day(), day);
+                    }
+                }
+            }
+        }
+    }
+
+    #[test]
+    fn test_mdf_with_fields() {
+        fn check(flags: YearFlags, month: u32, day: u32) {
+            let mdf = Mdf::new(month, day, flags).unwrap();
+
+            for month in range_inclusive(0u32, 16) {
+                let mdf = match mdf.with_month(month) {
+                    Some(mdf) => mdf,
+                    None if month > 12 => continue,
+                    None => panic!("failed to create Mdf with month {}", month),
+                };
+
+                if mdf.valid() {
+                    assert_eq!(mdf.month(), month);
+                    assert_eq!(mdf.day(), day);
+                }
+            }
+
+            for day in range_inclusive(0u32, 1024) {
+                let mdf = match mdf.with_day(day) {
+                    Some(mdf) => mdf,
+                    None if day > 31 => continue,
+                    None => panic!("failed to create Mdf with month {}", month),
+                };
+
+                if mdf.valid() {
+                    assert_eq!(mdf.month(), month);
+                    assert_eq!(mdf.day(), day);
+                }
+            }
+        }
+
+        for &flags in NONLEAP_FLAGS.iter() {
+            check(flags, 1, 1);
+            check(flags, 1, 31);
+            check(flags, 2, 1);
+            check(flags, 2, 28);
+            check(flags, 2, 29);
+            check(flags, 12, 31);
+        }
+        for &flags in LEAP_FLAGS.iter() {
+            check(flags, 1, 1);
+            check(flags, 1, 31);
+            check(flags, 2, 1);
+            check(flags, 2, 29);
+            check(flags, 2, 30);
+            check(flags, 12, 31);
+        }
+    }
+
+    #[test]
+    fn test_of_isoweekdate_raw() {
+        for &flags in FLAGS.iter() {
+            // January 4 should be in the first week
+            let (week, _) = Of::new(4 /* January 4 */, flags).unwrap().isoweekdate_raw();
+            assert_eq!(week, 1);
+        }
+    }
+
+    #[test]
+    fn test_of_to_mdf() {
+        for i in range_inclusive(0u32, 8192) {
+            let of = Of(i);
+            assert_eq!(of.valid(), of.to_mdf().valid());
+        }
+    }
+
+    #[test]
+    fn test_mdf_to_of() {
+        for i in range_inclusive(0u32, 8192) {
+            let mdf = Mdf(i);
+            assert_eq!(mdf.valid(), mdf.to_of().valid());
+        }
+    }
+
+    #[test]
+    fn test_of_to_mdf_to_of() {
+        for i in range_inclusive(0u32, 8192) {
+            let of = Of(i);
+            if of.valid() {
+                assert_eq!(of, of.to_mdf().to_of());
+            }
+        }
+    }
+
+    #[test]
+    fn test_mdf_to_of_to_mdf() {
+        for i in range_inclusive(0u32, 8192) {
+            let mdf = Mdf(i);
+            if mdf.valid() {
+                assert_eq!(mdf, mdf.to_of().to_mdf());
+            }
+        }
+    }
+}

javascript-engine/external/chrono/src/naive/isoweek.rs

@@ -0,0 +1,167 @@
+// This is a part of Chrono.
+// See README.md and LICENSE.txt for details.
+
+//! ISO 8601 week.
+
+use core::fmt;
+
+use super::internals::{DateImpl, Of, YearFlags};
+
+#[cfg(feature = "rkyv")]
+use rkyv::{Archive, Deserialize, Serialize};
+
+/// ISO 8601 week.
+///
+/// This type, combined with [`Weekday`](../enum.Weekday.html),
+/// constitutes the ISO 8601 [week date](./struct.NaiveDate.html#week-date).
+/// One can retrieve this type from the existing [`Datelike`](../trait.Datelike.html) types
+/// via the [`Datelike::iso_week`](../trait.Datelike.html#tymethod.iso_week) method.
+#[derive(PartialEq, Eq, PartialOrd, Ord, Copy, Clone)]
+#[cfg_attr(feature = "rkyv", derive(Archive, Deserialize, Serialize))]
+pub struct IsoWeek {
+    // note that this allows for larger year range than `NaiveDate`.
+    // this is crucial because we have an edge case for the first and last week supported,
+    // which year number might not match the calendar year number.
+    ywf: DateImpl, // (year << 10) | (week << 4) | flag
+}
+
+/// Returns the corresponding `IsoWeek` from the year and the `Of` internal value.
+//
+// internal use only. we don't expose the public constructor for `IsoWeek` for now,
+// because the year range for the week date and the calendar date do not match and
+// it is confusing to have a date that is out of range in one and not in another.
+// currently we sidestep this issue by making `IsoWeek` fully dependent of `Datelike`.
+pub(super) fn iso_week_from_yof(year: i32, of: Of) -> IsoWeek {
+    let (rawweek, _) = of.isoweekdate_raw();
+    let (year, week) = if rawweek < 1 {
+        // previous year
+        let prevlastweek = YearFlags::from_year(year - 1).nisoweeks();
+        (year - 1, prevlastweek)
+    } else {
+        let lastweek = of.flags().nisoweeks();
+        if rawweek > lastweek {
+            // next year
+            (year + 1, 1)
+        } else {
+            (year, rawweek)
+        }
+    };
+    IsoWeek { ywf: (year << 10) | (week << 4) as DateImpl | DateImpl::from(of.flags().0) }
+}
+
+impl IsoWeek {
+    /// Returns the year number for this ISO week.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use chrono::{NaiveDate, Datelike, Weekday};
+    ///
+    /// let d = NaiveDate::from_isoywd(2015, 1, Weekday::Mon);
+    /// assert_eq!(d.iso_week().year(), 2015);
+    /// ```
+    ///
+    /// This year number might not match the calendar year number.
+    /// Continuing the example...
+    ///
+    /// ```
+    /// # use chrono::{NaiveDate, Datelike, Weekday};
+    /// # let d = NaiveDate::from_isoywd(2015, 1, Weekday::Mon);
+    /// assert_eq!(d.year(), 2014);
+    /// assert_eq!(d, NaiveDate::from_ymd_opt(2014, 12, 29).unwrap());
+    /// ```
+    #[inline]
+    pub fn year(&self) -> i32 {
+        self.ywf >> 10
+    }
+
+    /// Returns the ISO week number starting from 1.
+    ///
+    /// The return value ranges from 1 to 53. (The last week of year differs by years.)
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use chrono::{NaiveDate, Datelike, Weekday};
+    ///
+    /// let d = NaiveDate::from_isoywd(2015, 15, Weekday::Mon);
+    /// assert_eq!(d.iso_week().week(), 15);
+    /// ```
+    #[inline]
+    pub fn week(&self) -> u32 {
+        ((self.ywf >> 4) & 0x3f) as u32
+    }
+
+    /// Returns the ISO week number starting from 0.
+    ///
+    /// The return value ranges from 0 to 52. (The last week of year differs by years.)
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use chrono::{NaiveDate, Datelike, Weekday};
+    ///
+    /// let d = NaiveDate::from_isoywd(2015, 15, Weekday::Mon);
+    /// assert_eq!(d.iso_week().week0(), 14);
+    /// ```
+    #[inline]
+    pub fn week0(&self) -> u32 {
+        ((self.ywf >> 4) & 0x3f) as u32 - 1
+    }
+}
+
+/// The `Debug` output of the ISO week `w` is the same as
+/// [`d.format("%G-W%V")`](../format/strftime/index.html)
+/// where `d` is any `NaiveDate` value in that week.
+///
+/// # Example
+///
+/// ```
+/// use chrono::{NaiveDate, Datelike};
+///
+/// assert_eq!(format!("{:?}", NaiveDate::from_ymd_opt(2015,  9,  5).unwrap().iso_week()), "2015-W36");
+/// assert_eq!(format!("{:?}", NaiveDate::from_ymd_opt(   0,  1,  3).unwrap().iso_week()), "0000-W01");
+/// assert_eq!(format!("{:?}", NaiveDate::from_ymd_opt(9999, 12, 31).unwrap().iso_week()), "9999-W52");
+/// ```
+///
+/// ISO 8601 requires an explicit sign for years before 1 BCE or after 9999 CE.
+///
+/// ```
+/// # use chrono::{NaiveDate, Datelike};
+/// assert_eq!(format!("{:?}", NaiveDate::from_ymd_opt(    0,  1,  2).unwrap().iso_week()),  "-0001-W52");
+/// assert_eq!(format!("{:?}", NaiveDate::from_ymd_opt(10000, 12, 31).unwrap().iso_week()), "+10000-W52");
+/// ```
+impl fmt::Debug for IsoWeek {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let year = self.year();
+        let week = self.week();
+        if (0..=9999).contains(&year) {
+            write!(f, "{:04}-W{:02}", year, week)
+        } else {
+            // ISO 8601 requires the explicit sign for out-of-range years
+            write!(f, "{:+05}-W{:02}", year, week)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::naive::{internals, NaiveDate};
+    use crate::Datelike;
+
+    #[test]
+    fn test_iso_week_extremes() {
+        let minweek = NaiveDate::MIN.iso_week();
+        let maxweek = NaiveDate::MAX.iso_week();
+
+        assert_eq!(minweek.year(), internals::MIN_YEAR);
+        assert_eq!(minweek.week(), 1);
+        assert_eq!(minweek.week0(), 0);
+        assert_eq!(format!("{:?}", minweek), NaiveDate::MIN.format("%G-W%V").to_string());
+
+        assert_eq!(maxweek.year(), internals::MAX_YEAR + 1);
+        assert_eq!(maxweek.week(), 1);
+        assert_eq!(maxweek.week0(), 0);
+        assert_eq!(format!("{:?}", maxweek), NaiveDate::MAX.format("%G-W%V").to_string());
+    }
+}

javascript-engine/external/chrono/src/naive/mod.rs

@@ -0,0 +1,39 @@
+//! Date and time types unconcerned with timezones.
+//!
+//! They are primarily building blocks for other types
+//! (e.g. [`TimeZone`](../offset/trait.TimeZone.html)),
+//! but can be also used for the simpler date and time handling.
+
+mod date;
+pub(crate) mod datetime;
+mod internals;
+mod isoweek;
+mod time;
+
+#[allow(deprecated)]
+pub use self::date::{Days, NaiveDate, NaiveWeek, MAX_DATE, MIN_DATE};
+#[cfg(feature = "rustc-serialize")]
+#[allow(deprecated)]
+pub use self::datetime::rustc_serialize::TsSeconds;
+#[allow(deprecated)]
+pub use self::datetime::{NaiveDateTime, MAX_DATETIME, MIN_DATETIME};
+pub use self::isoweek::IsoWeek;
+pub use self::time::NaiveTime;
+
+#[cfg(feature = "__internal_bench")]
+#[doc(hidden)]
+pub use self::internals::YearFlags as __BenchYearFlags;
+
+/// Serialization/Deserialization of naive types in alternate formats
+///
+/// The various modules in here are intended to be used with serde's [`with`
+/// annotation][1] to serialize as something other than the default [RFC
+/// 3339][2] format.
+///
+/// [1]: https://serde.rs/attributes.html#field-attributes
+/// [2]: https://tools.ietf.org/html/rfc3339
+#[cfg(feature = "serde")]
+#[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
+pub mod serde {
+    pub use super::datetime::serde::*;
+}

javascript-engine/external/chrono/src/naive/time/rustc_serialize.rs

@@ -0,0 +1,29 @@
+#![cfg_attr(docsrs, doc(cfg(feature = "rustc-serialize")))]
+
+use super::NaiveTime;
+use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
+
+impl Encodable for NaiveTime {
+    fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
+        format!("{:?}", self).encode(s)
+    }
+}
+
+impl Decodable for NaiveTime {
+    fn decode<D: Decoder>(d: &mut D) -> Result<NaiveTime, D::Error> {
+        d.read_str()?.parse().map_err(|_| d.error("invalid time"))
+    }
+}
+
+#[cfg(test)]
+use rustc_serialize::json;
+
+#[test]
+fn test_encodable() {
+    super::test_encodable_json(json::encode);
+}
+
+#[test]
+fn test_decodable() {
+    super::test_decodable_json(json::decode);
+}

javascript-engine/external/chrono/src/naive/time/serde.rs

@@ -0,0 +1,65 @@
+#![cfg_attr(docsrs, doc(cfg(feature = "serde")))]
+
+use super::NaiveTime;
+use core::fmt;
+use serde::{de, ser};
+
+// TODO not very optimized for space (binary formats would want something better)
+// TODO round-trip for general leap seconds (not just those with second = 60)
+
+impl ser::Serialize for NaiveTime {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: ser::Serializer,
+    {
+        serializer.collect_str(&self)
+    }
+}
+
+struct NaiveTimeVisitor;
+
+impl<'de> de::Visitor<'de> for NaiveTimeVisitor {
+    type Value = NaiveTime;
+
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("a formatted time string")
+    }
+
+    fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
+    where
+        E: de::Error,
+    {
+        value.parse().map_err(E::custom)
+    }
+}
+
+impl<'de> de::Deserialize<'de> for NaiveTime {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: de::Deserializer<'de>,
+    {
+        deserializer.deserialize_str(NaiveTimeVisitor)
+    }
+}
+
+#[test]
+fn test_serde_serialize() {
+    super::test_encodable_json(serde_json::to_string);
+}
+
+#[test]
+fn test_serde_deserialize() {
+    super::test_decodable_json(|input| serde_json::from_str(input));
+}
+
+#[test]
+fn test_serde_bincode() {
+    // Bincode is relevant to test separately from JSON because
+    // it is not self-describing.
+    use bincode::{deserialize, serialize};
+
+    let t = NaiveTime::from_hms_nano_opt(3, 5, 7, 98765432).unwrap();
+    let encoded = serialize(&t).unwrap();
+    let decoded: NaiveTime = deserialize(&encoded).unwrap();
+    assert_eq!(t, decoded);
+}

javascript-engine/external/chrono/src/naive/time/tests.rs

@@ -0,0 +1,317 @@
+use super::NaiveTime;
+use crate::oldtime::Duration;
+use crate::Timelike;
+use std::u32;
+
+#[test]
+fn test_time_from_hms_milli() {
+    assert_eq!(
+        NaiveTime::from_hms_milli_opt(3, 5, 7, 0),
+        Some(NaiveTime::from_hms_nano_opt(3, 5, 7, 0).unwrap())
+    );
+    assert_eq!(
+        NaiveTime::from_hms_milli_opt(3, 5, 7, 777),
+        Some(NaiveTime::from_hms_nano_opt(3, 5, 7, 777_000_000).unwrap())
+    );
+    assert_eq!(
+        NaiveTime::from_hms_milli_opt(3, 5, 7, 1_999),
+        Some(NaiveTime::from_hms_nano_opt(3, 5, 7, 1_999_000_000).unwrap())
+    );
+    assert_eq!(NaiveTime::from_hms_milli_opt(3, 5, 7, 2_000), None);
+    assert_eq!(NaiveTime::from_hms_milli_opt(3, 5, 7, 5_000), None); // overflow check
+    assert_eq!(NaiveTime::from_hms_milli_opt(3, 5, 7, u32::MAX), None);
+}
+
+#[test]
+fn test_time_from_hms_micro() {
+    assert_eq!(
+        NaiveTime::from_hms_micro_opt(3, 5, 7, 0),
+        Some(NaiveTime::from_hms_nano_opt(3, 5, 7, 0).unwrap())
+    );
+    assert_eq!(
+        NaiveTime::from_hms_micro_opt(3, 5, 7, 333),
+        Some(NaiveTime::from_hms_nano_opt(3, 5, 7, 333_000).unwrap())
+    );
+    assert_eq!(
+        NaiveTime::from_hms_micro_opt(3, 5, 7, 777_777),
+        Some(NaiveTime::from_hms_nano_opt(3, 5, 7, 777_777_000).unwrap())
+    );
+    assert_eq!(
+        NaiveTime::from_hms_micro_opt(3, 5, 7, 1_999_999),
+        Some(NaiveTime::from_hms_nano_opt(3, 5, 7, 1_999_999_000).unwrap())
+    );
+    assert_eq!(NaiveTime::from_hms_micro_opt(3, 5, 7, 2_000_000), None);
+    assert_eq!(NaiveTime::from_hms_micro_opt(3, 5, 7, 5_000_000), None); // overflow check
+    assert_eq!(NaiveTime::from_hms_micro_opt(3, 5, 7, u32::MAX), None);
+}
+
+#[test]
+fn test_time_hms() {
+    assert_eq!(NaiveTime::from_hms_opt(3, 5, 7).unwrap().hour(), 3);
+    assert_eq!(
+        NaiveTime::from_hms_opt(3, 5, 7).unwrap().with_hour(0),
+        Some(NaiveTime::from_hms_opt(0, 5, 7).unwrap())
+    );
+    assert_eq!(
+        NaiveTime::from_hms_opt(3, 5, 7).unwrap().with_hour(23),
+        Some(NaiveTime::from_hms_opt(23, 5, 7).unwrap())
+    );
+    assert_eq!(NaiveTime::from_hms_opt(3, 5, 7).unwrap().with_hour(24), None);
+    assert_eq!(NaiveTime::from_hms_opt(3, 5, 7).unwrap().with_hour(u32::MAX), None);
+
+    assert_eq!(NaiveTime::from_hms_opt(3, 5, 7).unwrap().minute(), 5);
+    assert_eq!(
+        NaiveTime::from_hms_opt(3, 5, 7).unwrap().with_minute(0),
+        Some(NaiveTime::from_hms_opt(3, 0, 7).unwrap())
+    );
+    assert_eq!(
+        NaiveTime::from_hms_opt(3, 5, 7).unwrap().with_minute(59),
+        Some(NaiveTime::from_hms_opt(3, 59, 7).unwrap())
+    );
+    assert_eq!(NaiveTime::from_hms_opt(3, 5, 7).unwrap().with_minute(60), None);
+    assert_eq!(NaiveTime::from_hms_opt(3, 5, 7).unwrap().with_minute(u32::MAX), None);
+
+    assert_eq!(NaiveTime::from_hms_opt(3, 5, 7).unwrap().second(), 7);
+    assert_eq!(
+        NaiveTime::from_hms_opt(3, 5, 7).unwrap().with_second(0),
+        Some(NaiveTime::from_hms_opt(3, 5, 0).unwrap())
+    );
+    assert_eq!(
+        NaiveTime::from_hms_opt(3, 5, 7).unwrap().with_second(59),
+        Some(NaiveTime::from_hms_opt(3, 5, 59).unwrap())
+    );
+    assert_eq!(NaiveTime::from_hms_opt(3, 5, 7).unwrap().with_second(60), None);
+    assert_eq!(NaiveTime::from_hms_opt(3, 5, 7).unwrap().with_second(u32::MAX), None);
+}
+
+#[test]
+fn test_time_add() {
+    macro_rules! check {
+        ($lhs:expr, $rhs:expr, $sum:expr) => {{
+            assert_eq!($lhs + $rhs, $sum);
+            //assert_eq!($rhs + $lhs, $sum);
+        }};
+    }
+
+    let hmsm = |h, m, s, ms| NaiveTime::from_hms_milli_opt(h, m, s, ms).unwrap();
+
+    check!(hmsm(3, 5, 7, 900), Duration::zero(), hmsm(3, 5, 7, 900));
+    check!(hmsm(3, 5, 7, 900), Duration::milliseconds(100), hmsm(3, 5, 8, 0));
+    check!(hmsm(3, 5, 7, 1_300), Duration::milliseconds(-1800), hmsm(3, 5, 6, 500));
+    check!(hmsm(3, 5, 7, 1_300), Duration::milliseconds(-800), hmsm(3, 5, 7, 500));
+    check!(hmsm(3, 5, 7, 1_300), Duration::milliseconds(-100), hmsm(3, 5, 7, 1_200));
+    check!(hmsm(3, 5, 7, 1_300), Duration::milliseconds(100), hmsm(3, 5, 7, 1_400));
+    check!(hmsm(3, 5, 7, 1_300), Duration::milliseconds(800), hmsm(3, 5, 8, 100));
+    check!(hmsm(3, 5, 7, 1_300), Duration::milliseconds(1800), hmsm(3, 5, 9, 100));
+    check!(hmsm(3, 5, 7, 900), Duration::seconds(86399), hmsm(3, 5, 6, 900)); // overwrap
+    check!(hmsm(3, 5, 7, 900), Duration::seconds(-86399), hmsm(3, 5, 8, 900));
+    check!(hmsm(3, 5, 7, 900), Duration::days(12345), hmsm(3, 5, 7, 900));
+    check!(hmsm(3, 5, 7, 1_300), Duration::days(1), hmsm(3, 5, 7, 300));
+    check!(hmsm(3, 5, 7, 1_300), Duration::days(-1), hmsm(3, 5, 8, 300));
+
+    // regression tests for #37
+    check!(hmsm(0, 0, 0, 0), Duration::milliseconds(-990), hmsm(23, 59, 59, 10));
+    check!(hmsm(0, 0, 0, 0), Duration::milliseconds(-9990), hmsm(23, 59, 50, 10));
+}
+
+#[test]
+fn test_time_overflowing_add() {
+    let hmsm = |h, m, s, ms| NaiveTime::from_hms_milli_opt(h, m, s, ms).unwrap();
+
+    assert_eq!(
+        hmsm(3, 4, 5, 678).overflowing_add_signed(Duration::hours(11)),
+        (hmsm(14, 4, 5, 678), 0)
+    );
+    assert_eq!(
+        hmsm(3, 4, 5, 678).overflowing_add_signed(Duration::hours(23)),
+        (hmsm(2, 4, 5, 678), 86_400)
+    );
+    assert_eq!(
+        hmsm(3, 4, 5, 678).overflowing_add_signed(Duration::hours(-7)),
+        (hmsm(20, 4, 5, 678), -86_400)
+    );
+
+    // overflowing_add_signed with leap seconds may be counter-intuitive
+    assert_eq!(
+        hmsm(3, 4, 5, 1_678).overflowing_add_signed(Duration::days(1)),
+        (hmsm(3, 4, 5, 678), 86_400)
+    );
+    assert_eq!(
+        hmsm(3, 4, 5, 1_678).overflowing_add_signed(Duration::days(-1)),
+        (hmsm(3, 4, 6, 678), -86_400)
+    );
+}
+
+#[test]
+fn test_time_addassignment() {
+    let hms = |h, m, s| NaiveTime::from_hms_opt(h, m, s).unwrap();
+    let mut time = hms(12, 12, 12);
+    time += Duration::hours(10);
+    assert_eq!(time, hms(22, 12, 12));
+    time += Duration::hours(10);
+    assert_eq!(time, hms(8, 12, 12));
+}
+
+#[test]
+fn test_time_subassignment() {
+    let hms = |h, m, s| NaiveTime::from_hms_opt(h, m, s).unwrap();
+    let mut time = hms(12, 12, 12);
+    time -= Duration::hours(10);
+    assert_eq!(time, hms(2, 12, 12));
+    time -= Duration::hours(10);
+    assert_eq!(time, hms(16, 12, 12));
+}
+
+#[test]
+fn test_time_sub() {
+    macro_rules! check {
+        ($lhs:expr, $rhs:expr, $diff:expr) => {{
+            // `time1 - time2 = duration` is equivalent to `time2 - time1 = -duration`
+            assert_eq!($lhs.signed_duration_since($rhs), $diff);
+            assert_eq!($rhs.signed_duration_since($lhs), -$diff);
+        }};
+    }
+
+    let hmsm = |h, m, s, ms| NaiveTime::from_hms_milli_opt(h, m, s, ms).unwrap();
+
+    check!(hmsm(3, 5, 7, 900), hmsm(3, 5, 7, 900), Duration::zero());
+    check!(hmsm(3, 5, 7, 900), hmsm(3, 5, 7, 600), Duration::milliseconds(300));
+    check!(hmsm(3, 5, 7, 200), hmsm(2, 4, 6, 200), Duration::seconds(3600 + 60 + 1));
+    check!(
+        hmsm(3, 5, 7, 200),
+        hmsm(2, 4, 6, 300),
+        Duration::seconds(3600 + 60) + Duration::milliseconds(900)
+    );
+
+    // treats the leap second as if it coincides with the prior non-leap second,
+    // as required by `time1 - time2 = duration` and `time2 - time1 = -duration` equivalence.
+    check!(hmsm(3, 5, 7, 200), hmsm(3, 5, 6, 1_800), Duration::milliseconds(400));
+    check!(hmsm(3, 5, 7, 1_200), hmsm(3, 5, 6, 1_800), Duration::milliseconds(1400));
+    check!(hmsm(3, 5, 7, 1_200), hmsm(3, 5, 6, 800), Duration::milliseconds(1400));
+
+    // additional equality: `time1 + duration = time2` is equivalent to
+    // `time2 - time1 = duration` IF AND ONLY IF `time2` represents a non-leap second.
+    assert_eq!(hmsm(3, 5, 6, 800) + Duration::milliseconds(400), hmsm(3, 5, 7, 200));
+    assert_eq!(hmsm(3, 5, 6, 1_800) + Duration::milliseconds(400), hmsm(3, 5, 7, 200));
+}
+
+#[test]
+fn test_time_fmt() {
+    assert_eq!(
+        format!("{}", NaiveTime::from_hms_milli_opt(23, 59, 59, 999).unwrap()),
+        "23:59:59.999"
+    );
+    assert_eq!(
+        format!("{}", NaiveTime::from_hms_milli_opt(23, 59, 59, 1_000).unwrap()),
+        "23:59:60"
+    );
+    assert_eq!(
+        format!("{}", NaiveTime::from_hms_milli_opt(23, 59, 59, 1_001).unwrap()),
+        "23:59:60.001"
+    );
+    assert_eq!(
+        format!("{}", NaiveTime::from_hms_micro_opt(0, 0, 0, 43210).unwrap()),
+        "00:00:00.043210"
+    );
+    assert_eq!(
+        format!("{}", NaiveTime::from_hms_nano_opt(0, 0, 0, 6543210).unwrap()),
+        "00:00:00.006543210"
+    );
+
+    // the format specifier should have no effect on `NaiveTime`
+    assert_eq!(
+        format!("{:30}", NaiveTime::from_hms_milli_opt(3, 5, 7, 9).unwrap()),
+        "03:05:07.009"
+    );
+}
+
+#[test]
+fn test_date_from_str() {
+    // valid cases
+    let valid = [
+        "0:0:0",
+        "0:0:0.0000000",
+        "0:0:0.0000003",
+        " 4 : 3 : 2.1 ",
+        " 09:08:07 ",
+        " 9:8:07 ",
+        "23:59:60.373929310237",
+    ];
+    for &s in &valid {
+        let d = match s.parse::<NaiveTime>() {
+            Ok(d) => d,
+            Err(e) => panic!("parsing `{}` has failed: {}", s, e),
+        };
+        let s_ = format!("{:?}", d);
+        // `s` and `s_` may differ, but `s.parse()` and `s_.parse()` must be same
+        let d_ = match s_.parse::<NaiveTime>() {
+            Ok(d) => d,
+            Err(e) => {
+                panic!("`{}` is parsed into `{:?}`, but reparsing that has failed: {}", s, d, e)
+            }
+        };
+        assert!(
+            d == d_,
+            "`{}` is parsed into `{:?}`, but reparsed result \
+                              `{:?}` does not match",
+            s,
+            d,
+            d_
+        );
+    }
+
+    // some invalid cases
+    // since `ParseErrorKind` is private, all we can do is to check if there was an error
+    assert!("".parse::<NaiveTime>().is_err());
+    assert!("x".parse::<NaiveTime>().is_err());
+    assert!("15".parse::<NaiveTime>().is_err());
+    assert!("15:8".parse::<NaiveTime>().is_err());
+    assert!("15:8:x".parse::<NaiveTime>().is_err());
+    assert!("15:8:9x".parse::<NaiveTime>().is_err());
+    assert!("23:59:61".parse::<NaiveTime>().is_err());
+    assert!("12:34:56.x".parse::<NaiveTime>().is_err());
+    assert!("12:34:56. 0".parse::<NaiveTime>().is_err());
+}
+
+#[test]
+fn test_time_parse_from_str() {
+    let hms = |h, m, s| NaiveTime::from_hms_opt(h, m, s).unwrap();
+    assert_eq!(
+        NaiveTime::parse_from_str("2014-5-7T12:34:56+09:30", "%Y-%m-%dT%H:%M:%S%z"),
+        Ok(hms(12, 34, 56))
+    ); // ignore date and offset
+    assert_eq!(NaiveTime::parse_from_str("PM 12:59", "%P %H:%M"), Ok(hms(12, 59, 0)));
+    assert!(NaiveTime::parse_from_str("12:3456", "%H:%M:%S").is_err());
+}
+
+#[test]
+fn test_time_format() {
+    let t = NaiveTime::from_hms_nano_opt(3, 5, 7, 98765432).unwrap();
+    assert_eq!(t.format("%H,%k,%I,%l,%P,%p").to_string(), "03, 3,03, 3,am,AM");
+    assert_eq!(t.format("%M").to_string(), "05");
+    assert_eq!(t.format("%S,%f,%.f").to_string(), "07,098765432,.098765432");
+    assert_eq!(t.format("%.3f,%.6f,%.9f").to_string(), ".098,.098765,.098765432");
+    assert_eq!(t.format("%R").to_string(), "03:05");
+    assert_eq!(t.format("%T,%X").to_string(), "03:05:07,03:05:07");
+    assert_eq!(t.format("%r").to_string(), "03:05:07 AM");
+    assert_eq!(t.format("%t%n%%%n%t").to_string(), "\t\n%\n\t");
+
+    let t = NaiveTime::from_hms_micro_opt(3, 5, 7, 432100).unwrap();
+    assert_eq!(t.format("%S,%f,%.f").to_string(), "07,432100000,.432100");
+    assert_eq!(t.format("%.3f,%.6f,%.9f").to_string(), ".432,.432100,.432100000");
+
+    let t = NaiveTime::from_hms_milli_opt(3, 5, 7, 210).unwrap();
+    assert_eq!(t.format("%S,%f,%.f").to_string(), "07,210000000,.210");
+    assert_eq!(t.format("%.3f,%.6f,%.9f").to_string(), ".210,.210000,.210000000");
+
+    let t = NaiveTime::from_hms_opt(3, 5, 7).unwrap();
+    assert_eq!(t.format("%S,%f,%.f").to_string(), "07,000000000,");
+    assert_eq!(t.format("%.3f,%.6f,%.9f").to_string(), ".000,.000000,.000000000");
+
+    // corner cases
+    assert_eq!(NaiveTime::from_hms_opt(13, 57, 9).unwrap().format("%r").to_string(), "01:57:09 PM");
+    assert_eq!(
+        NaiveTime::from_hms_milli_opt(23, 59, 59, 1_000).unwrap().format("%X").to_string(),
+        "23:59:60"
+    );
+}

javascript-engine/external/chrono/src/offset/fixed.rs

@@ -0,0 +1,284 @@
+// This is a part of Chrono.
+// See README.md and LICENSE.txt for details.
+
+//! The time zone which has a fixed offset from UTC.
+
+use core::fmt;
+use core::ops::{Add, Sub};
+
+use num_integer::div_mod_floor;
+#[cfg(feature = "rkyv")]
+use rkyv::{Archive, Deserialize, Serialize};
+
+use super::{LocalResult, Offset, TimeZone};
+use crate::naive::{NaiveDate, NaiveDateTime, NaiveTime};
+use crate::oldtime::Duration as OldDuration;
+use crate::DateTime;
+use crate::Timelike;
+
+/// The time zone with fixed offset, from UTC-23:59:59 to UTC+23:59:59.
+///
+/// Using the [`TimeZone`](./trait.TimeZone.html) methods
+/// on a `FixedOffset` struct is the preferred way to construct
+/// `DateTime<FixedOffset>` instances. See the [`east`](#method.east) and
+/// [`west`](#method.west) methods for examples.
+#[derive(PartialEq, Eq, Hash, Copy, Clone)]
+#[cfg_attr(feature = "rkyv", derive(Archive, Deserialize, Serialize))]
+pub struct FixedOffset {
+    local_minus_utc: i32,
+}
+
+impl FixedOffset {
+    /// Makes a new `FixedOffset` for the Eastern Hemisphere with given timezone difference.
+    /// The negative `secs` means the Western Hemisphere.
+    ///
+    /// Panics on the out-of-bound `secs`.
+    #[deprecated(since = "0.4.23", note = "use `east_opt()` instead")]
+    pub fn east(secs: i32) -> FixedOffset {
+        FixedOffset::east_opt(secs).expect("FixedOffset::east out of bounds")
+    }
+
+    /// Makes a new `FixedOffset` for the Eastern Hemisphere with given timezone difference.
+    /// The negative `secs` means the Western Hemisphere.
+    ///
+    /// Returns `None` on the out-of-bound `secs`.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use chrono::{FixedOffset, TimeZone};
+    /// let hour = 3600;
+    /// let datetime = FixedOffset::east_opt(5 * hour).unwrap().ymd_opt(2016, 11, 08).unwrap()
+    ///                                           .and_hms_opt(0, 0, 0).unwrap();
+    /// assert_eq!(&datetime.to_rfc3339(), "2016-11-08T00:00:00+05:00")
+    /// ```
+    pub fn east_opt(secs: i32) -> Option<FixedOffset> {
+        if -86_400 < secs && secs < 86_400 {
+            Some(FixedOffset { local_minus_utc: secs })
+        } else {
+            None
+        }
+    }
+
+    /// Makes a new `FixedOffset` for the Western Hemisphere with given timezone difference.
+    /// The negative `secs` means the Eastern Hemisphere.
+    ///
+    /// Panics on the out-of-bound `secs`.
+    #[deprecated(since = "0.4.23", note = "use `west_opt()` instead")]
+    pub fn west(secs: i32) -> FixedOffset {
+        FixedOffset::west_opt(secs).expect("FixedOffset::west out of bounds")
+    }
+
+    /// Makes a new `FixedOffset` for the Western Hemisphere with given timezone difference.
+    /// The negative `secs` means the Eastern Hemisphere.
+    ///
+    /// Returns `None` on the out-of-bound `secs`.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use chrono::{FixedOffset, TimeZone};
+    /// let hour = 3600;
+    /// let datetime = FixedOffset::west_opt(5 * hour).unwrap().ymd_opt(2016, 11, 08).unwrap()
+    ///                                           .and_hms_opt(0, 0, 0).unwrap();
+    /// assert_eq!(&datetime.to_rfc3339(), "2016-11-08T00:00:00-05:00")
+    /// ```
+    pub fn west_opt(secs: i32) -> Option<FixedOffset> {
+        if -86_400 < secs && secs < 86_400 {
+            Some(FixedOffset { local_minus_utc: -secs })
+        } else {
+            None
+        }
+    }
+
+    /// Returns the number of seconds to add to convert from UTC to the local time.
+    #[inline]
+    pub fn local_minus_utc(&self) -> i32 {
+        self.local_minus_utc
+    }
+
+    /// Returns the number of seconds to add to convert from the local time to UTC.
+    #[inline]
+    pub fn utc_minus_local(&self) -> i32 {
+        -self.local_minus_utc
+    }
+}
+
+impl TimeZone for FixedOffset {
+    type Offset = FixedOffset;
+
+    fn from_offset(offset: &FixedOffset) -> FixedOffset {
+        *offset
+    }
+
+    fn offset_from_local_date(&self, _local: &NaiveDate) -> LocalResult<FixedOffset> {
+        LocalResult::Single(*self)
+    }
+    fn offset_from_local_datetime(&self, _local: &NaiveDateTime) -> LocalResult<FixedOffset> {
+        LocalResult::Single(*self)
+    }
+
+    fn offset_from_utc_date(&self, _utc: &NaiveDate) -> FixedOffset {
+        *self
+    }
+    fn offset_from_utc_datetime(&self, _utc: &NaiveDateTime) -> FixedOffset {
+        *self
+    }
+}
+
+impl Offset for FixedOffset {
+    fn fix(&self) -> FixedOffset {
+        *self
+    }
+}
+
+impl fmt::Debug for FixedOffset {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let offset = self.local_minus_utc;
+        let (sign, offset) = if offset < 0 { ('-', -offset) } else { ('+', offset) };
+        let (mins, sec) = div_mod_floor(offset, 60);
+        let (hour, min) = div_mod_floor(mins, 60);
+        if sec == 0 {
+            write!(f, "{}{:02}:{:02}", sign, hour, min)
+        } else {
+            write!(f, "{}{:02}:{:02}:{:02}", sign, hour, min, sec)
+        }
+    }
+}
+
+impl fmt::Display for FixedOffset {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::Debug::fmt(self, f)
+    }
+}
+
+#[cfg(feature = "arbitrary")]
+impl arbitrary::Arbitrary<'_> for FixedOffset {
+    fn arbitrary(u: &mut arbitrary::Unstructured) -> arbitrary::Result<FixedOffset> {
+        let secs = u.int_in_range(-86_399..=86_399)?;
+        let fixed_offset = FixedOffset::east_opt(secs)
+            .expect("Could not generate a valid chrono::FixedOffset. It looks like implementation of Arbitrary for FixedOffset is erroneous.");
+        Ok(fixed_offset)
+    }
+}
+
+// addition or subtraction of FixedOffset to/from Timelike values is the same as
+// adding or subtracting the offset's local_minus_utc value
+// but keep keeps the leap second information.
+// this should be implemented more efficiently, but for the time being, this is generic right now.
+
+fn add_with_leapsecond<T>(lhs: &T, rhs: i32) -> T
+where
+    T: Timelike + Add<OldDuration, Output = T>,
+{
+    // extract and temporarily remove the fractional part and later recover it
+    let nanos = lhs.nanosecond();
+    let lhs = lhs.with_nanosecond(0).unwrap();
+    (lhs + OldDuration::seconds(i64::from(rhs))).with_nanosecond(nanos).unwrap()
+}
+
+impl Add<FixedOffset> for NaiveTime {
+    type Output = NaiveTime;
+
+    #[inline]
+    fn add(self, rhs: FixedOffset) -> NaiveTime {
+        add_with_leapsecond(&self, rhs.local_minus_utc)
+    }
+}
+
+impl Sub<FixedOffset> for NaiveTime {
+    type Output = NaiveTime;
+
+    #[inline]
+    fn sub(self, rhs: FixedOffset) -> NaiveTime {
+        add_with_leapsecond(&self, -rhs.local_minus_utc)
+    }
+}
+
+impl Add<FixedOffset> for NaiveDateTime {
+    type Output = NaiveDateTime;
+
+    #[inline]
+    fn add(self, rhs: FixedOffset) -> NaiveDateTime {
+        add_with_leapsecond(&self, rhs.local_minus_utc)
+    }
+}
+
+impl Sub<FixedOffset> for NaiveDateTime {
+    type Output = NaiveDateTime;
+
+    #[inline]
+    fn sub(self, rhs: FixedOffset) -> NaiveDateTime {
+        add_with_leapsecond(&self, -rhs.local_minus_utc)
+    }
+}
+
+impl<Tz: TimeZone> Add<FixedOffset> for DateTime<Tz> {
+    type Output = DateTime<Tz>;
+
+    #[inline]
+    fn add(self, rhs: FixedOffset) -> DateTime<Tz> {
+        add_with_leapsecond(&self, rhs.local_minus_utc)
+    }
+}
+
+impl<Tz: TimeZone> Sub<FixedOffset> for DateTime<Tz> {
+    type Output = DateTime<Tz>;
+
+    #[inline]
+    fn sub(self, rhs: FixedOffset) -> DateTime<Tz> {
+        add_with_leapsecond(&self, -rhs.local_minus_utc)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::FixedOffset;
+    use crate::offset::TimeZone;
+
+    #[test]
+    fn test_date_extreme_offset() {
+        // starting from 0.3 we don't have an offset exceeding one day.
+        // this makes everything easier!
+        assert_eq!(
+            format!(
+                "{:?}",
+                FixedOffset::east_opt(86399)
+                    .unwrap()
+                    .with_ymd_and_hms(2012, 2, 29, 5, 6, 7)
+                    .unwrap()
+            ),
+            "2012-02-29T05:06:07+23:59:59".to_string()
+        );
+        assert_eq!(
+            format!(
+                "{:?}",
+                FixedOffset::east_opt(86399)
+                    .unwrap()
+                    .with_ymd_and_hms(2012, 2, 29, 5, 6, 7)
+                    .unwrap()
+            ),
+            "2012-02-29T05:06:07+23:59:59".to_string()
+        );
+        assert_eq!(
+            format!(
+                "{:?}",
+                FixedOffset::west_opt(86399)
+                    .unwrap()
+                    .with_ymd_and_hms(2012, 3, 4, 5, 6, 7)
+                    .unwrap()
+            ),
+            "2012-03-04T05:06:07-23:59:59".to_string()
+        );
+        assert_eq!(
+            format!(
+                "{:?}",
+                FixedOffset::west_opt(86399)
+                    .unwrap()
+                    .with_ymd_and_hms(2012, 3, 4, 5, 6, 7)
+                    .unwrap()
+            ),
+            "2012-03-04T05:06:07-23:59:59".to_string()
+        );
+    }
+}

javascript-engine/external/chrono/src/offset/local/mod.rs

@@ -0,0 +1,260 @@
+// This is a part of Chrono.
+// See README.md and LICENSE.txt for details.
+
+//! The local (system) time zone.
+
+#[cfg(feature = "rkyv")]
+use rkyv::{Archive, Deserialize, Serialize};
+
+use super::fixed::FixedOffset;
+use super::{LocalResult, TimeZone};
+use crate::naive::{NaiveDate, NaiveDateTime};
+#[allow(deprecated)]
+use crate::{Date, DateTime};
+
+// we don't want `stub.rs` when the target_os is not wasi or emscripten
+// as we use js-sys to get the date instead
+#[cfg(all(
+    not(unix),
+    not(windows),
+    not(all(
+        target_arch = "wasm32",
+        feature = "wasmbind",
+        not(any(target_os = "emscripten", target_os = "wasi"))
+    ))
+))]
+#[path = "stub.rs"]
+mod inner;
+
+#[cfg(unix)]
+#[path = "unix.rs"]
+mod inner;
+
+#[cfg(windows)]
+#[path = "windows.rs"]
+mod inner;
+
+#[cfg(unix)]
+mod tz_info;
+
+/// The local timescale. This is implemented via the standard `time` crate.
+///
+/// Using the [`TimeZone`](./trait.TimeZone.html) methods
+/// on the Local struct is the preferred way to construct `DateTime<Local>`
+/// instances.
+///
+/// # Example
+///
+/// ```
+/// use chrono::{Local, DateTime, TimeZone};
+///
+/// let dt: DateTime<Local> = Local::now();
+/// let dt: DateTime<Local> = Local.timestamp(0, 0);
+/// ```
+#[derive(Copy, Clone, Debug)]
+#[cfg_attr(feature = "rkyv", derive(Archive, Deserialize, Serialize))]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
+pub struct Local;
+
+impl Local {
+    /// Returns a `Date` which corresponds to the current date.
+    #[deprecated(since = "0.4.23", note = "use `Local::now()` instead")]
+    #[allow(deprecated)]
+    pub fn today() -> Date<Local> {
+        Local::now().date()
+    }
+
+    /// Returns a `DateTime` which corresponds to the current date and time.
+    #[cfg(not(all(
+        target_arch = "wasm32",
+        feature = "wasmbind",
+        not(any(target_os = "emscripten", target_os = "wasi"))
+    )))]
+    pub fn now() -> DateTime<Local> {
+        inner::now()
+    }
+
+    /// Returns a `DateTime` which corresponds to the current date and time.
+    #[cfg(all(
+        target_arch = "wasm32",
+        feature = "wasmbind",
+        not(any(target_os = "emscripten", target_os = "wasi"))
+    ))]
+    pub fn now() -> DateTime<Local> {
+        use super::Utc;
+        let now: DateTime<Utc> = super::Utc::now();
+
+        // Workaround missing timezone logic in `time` crate
+        let offset =
+            FixedOffset::west_opt((js_sys::Date::new_0().get_timezone_offset() as i32) * 60)
+                .unwrap();
+        DateTime::from_utc(now.naive_utc(), offset)
+    }
+}
+
+impl TimeZone for Local {
+    type Offset = FixedOffset;
+
+    fn from_offset(_offset: &FixedOffset) -> Local {
+        Local
+    }
+
+    // they are easier to define in terms of the finished date and time unlike other offsets
+    #[allow(deprecated)]
+    fn offset_from_local_date(&self, local: &NaiveDate) -> LocalResult<FixedOffset> {
+        self.from_local_date(local).map(|date| *date.offset())
+    }
+
+    fn offset_from_local_datetime(&self, local: &NaiveDateTime) -> LocalResult<FixedOffset> {
+        self.from_local_datetime(local).map(|datetime| *datetime.offset())
+    }
+
+    #[allow(deprecated)]
+    fn offset_from_utc_date(&self, utc: &NaiveDate) -> FixedOffset {
+        *self.from_utc_date(utc).offset()
+    }
+
+    fn offset_from_utc_datetime(&self, utc: &NaiveDateTime) -> FixedOffset {
+        *self.from_utc_datetime(utc).offset()
+    }
+
+    // override them for avoiding redundant works
+    #[allow(deprecated)]
+    fn from_local_date(&self, local: &NaiveDate) -> LocalResult<Date<Local>> {
+        // this sounds very strange, but required for keeping `TimeZone::ymd` sane.
+        // in the other words, we use the offset at the local midnight
+        // but keep the actual date unaltered (much like `FixedOffset`).
+        let midnight = self.from_local_datetime(&local.and_hms_opt(0, 0, 0).unwrap());
+        midnight.map(|datetime| Date::from_utc(*local, *datetime.offset()))
+    }
+
+    #[cfg(all(
+        target_arch = "wasm32",
+        feature = "wasmbind",
+        not(any(target_os = "emscripten", target_os = "wasi"))
+    ))]
+    fn from_local_datetime(&self, local: &NaiveDateTime) -> LocalResult<DateTime<Local>> {
+        let mut local = local.clone();
+        // Get the offset from the js runtime
+        let offset =
+            FixedOffset::west_opt((js_sys::Date::new_0().get_timezone_offset() as i32) * 60)
+                .unwrap();
+        local -= crate::Duration::seconds(offset.local_minus_utc() as i64);
+        LocalResult::Single(DateTime::from_utc(local, offset))
+    }
+
+    #[cfg(not(all(
+        target_arch = "wasm32",
+        feature = "wasmbind",
+        not(any(target_os = "emscripten", target_os = "wasi"))
+    )))]
+    fn from_local_datetime(&self, local: &NaiveDateTime) -> LocalResult<DateTime<Local>> {
+        inner::naive_to_local(local, true)
+    }
+
+    #[allow(deprecated)]
+    fn from_utc_date(&self, utc: &NaiveDate) -> Date<Local> {
+        let midnight = self.from_utc_datetime(&utc.and_hms_opt(0, 0, 0).unwrap());
+        Date::from_utc(*utc, *midnight.offset())
+    }
+
+    #[cfg(all(
+        target_arch = "wasm32",
+        feature = "wasmbind",
+        not(any(target_os = "emscripten", target_os = "wasi"))
+    ))]
+    fn from_utc_datetime(&self, utc: &NaiveDateTime) -> DateTime<Local> {
+        // Get the offset from the js runtime
+        let offset =
+            FixedOffset::west_opt((js_sys::Date::new_0().get_timezone_offset() as i32) * 60)
+                .unwrap();
+        DateTime::from_utc(*utc, offset)
+    }
+
+    #[cfg(not(all(
+        target_arch = "wasm32",
+        feature = "wasmbind",
+        not(any(target_os = "emscripten", target_os = "wasi"))
+    )))]
+    fn from_utc_datetime(&self, utc: &NaiveDateTime) -> DateTime<Local> {
+        // this is OK to unwrap as getting local time from a UTC
+        // timestamp is never ambiguous
+        inner::naive_to_local(utc, false).unwrap()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Local;
+    use crate::offset::TimeZone;
+    use crate::{Datelike, Duration, Utc};
+
+    #[test]
+    fn verify_correct_offsets() {
+        let now = Local::now();
+        let from_local = Local.from_local_datetime(&now.naive_local()).unwrap();
+        let from_utc = Local.from_utc_datetime(&now.naive_utc());
+
+        assert_eq!(now.offset().local_minus_utc(), from_local.offset().local_minus_utc());
+        assert_eq!(now.offset().local_minus_utc(), from_utc.offset().local_minus_utc());
+
+        assert_eq!(now, from_local);
+        assert_eq!(now, from_utc);
+    }
+
+    #[test]
+    fn verify_correct_offsets_distant_past() {
+        // let distant_past = Local::now() - Duration::days(365 * 100);
+        let distant_past = Local::now() - Duration::days(250 * 31);
+        let from_local = Local.from_local_datetime(&distant_past.naive_local()).unwrap();
+        let from_utc = Local.from_utc_datetime(&distant_past.naive_utc());
+
+        assert_eq!(distant_past.offset().local_minus_utc(), from_local.offset().local_minus_utc());
+        assert_eq!(distant_past.offset().local_minus_utc(), from_utc.offset().local_minus_utc());
+
+        assert_eq!(distant_past, from_local);
+        assert_eq!(distant_past, from_utc);
+    }
+
+    #[test]
+    fn verify_correct_offsets_distant_future() {
+        let distant_future = Local::now() + Duration::days(250 * 31);
+        let from_local = Local.from_local_datetime(&distant_future.naive_local()).unwrap();
+        let from_utc = Local.from_utc_datetime(&distant_future.naive_utc());
+
+        assert_eq!(
+            distant_future.offset().local_minus_utc(),
+            from_local.offset().local_minus_utc()
+        );
+        assert_eq!(distant_future.offset().local_minus_utc(), from_utc.offset().local_minus_utc());
+
+        assert_eq!(distant_future, from_local);
+        assert_eq!(distant_future, from_utc);
+    }
+
+    #[test]
+    fn test_local_date_sanity_check() {
+        // issue #27
+        assert_eq!(Local.with_ymd_and_hms(2999, 12, 28, 0, 0, 0).unwrap().day(), 28);
+    }
+
+    #[test]
+    fn test_leap_second() {
+        // issue #123
+        let today = Utc::now().date_naive();
+
+        let dt = today.and_hms_milli_opt(1, 2, 59, 1000).unwrap();
+        let timestr = dt.time().to_string();
+        // the OS API may or may not support the leap second,
+        // but there are only two sensible options.
+        assert!(timestr == "01:02:60" || timestr == "01:03:00", "unexpected timestr {:?}", timestr);
+
+        let dt = today.and_hms_milli_opt(1, 2, 3, 1234).unwrap();
+        let timestr = dt.time().to_string();
+        assert!(
+            timestr == "01:02:03.234" || timestr == "01:02:04.234",
+            "unexpected timestr {:?}",
+            timestr
+        );
+    }
+}

javascript-engine/external/chrono/src/offset/local/stub.rs

@@ -0,0 +1,237 @@
+// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use super::{FixedOffset, Local};
+use crate::{DateTime, Datelike, LocalResult, NaiveDate, NaiveDateTime, NaiveTime, Timelike};
+
+pub(super) fn now() -> DateTime<Local> {
+    tm_to_datetime(Timespec::now().local())
+}
+
+/// Converts a local `NaiveDateTime` to the `time::Timespec`.
+#[cfg(not(all(
+    target_arch = "wasm32",
+    feature = "wasmbind",
+    not(any(target_os = "emscripten", target_os = "wasi"))
+)))]
+pub(super) fn naive_to_local(d: &NaiveDateTime, local: bool) -> LocalResult<DateTime<Local>> {
+    let tm = Tm {
+        tm_sec: d.second() as i32,
+        tm_min: d.minute() as i32,
+        tm_hour: d.hour() as i32,
+        tm_mday: d.day() as i32,
+        tm_mon: d.month0() as i32, // yes, C is that strange...
+        tm_year: d.year() - 1900,  // this doesn't underflow, we know that d is `NaiveDateTime`.
+        tm_wday: 0,                // to_local ignores this
+        tm_yday: 0,                // and this
+        tm_isdst: -1,
+        // This seems pretty fake?
+        tm_utcoff: if local { 1 } else { 0 },
+        // do not set this, OS APIs are heavily inconsistent in terms of leap second handling
+        tm_nsec: 0,
+    };
+
+    let spec = Timespec {
+        sec: match local {
+            false => utc_tm_to_time(&tm),
+            true => local_tm_to_time(&tm),
+        },
+        nsec: tm.tm_nsec,
+    };
+
+    // Adjust for leap seconds
+    let mut tm = spec.local();
+    assert_eq!(tm.tm_nsec, 0);
+    tm.tm_nsec = d.nanosecond() as i32;
+
+    LocalResult::Single(tm_to_datetime(tm))
+}
+
+/// Converts a `time::Tm` struct into the timezone-aware `DateTime`.
+/// This assumes that `time` is working correctly, i.e. any error is fatal.
+#[cfg(not(all(
+    target_arch = "wasm32",
+    feature = "wasmbind",
+    not(any(target_os = "emscripten", target_os = "wasi"))
+)))]
+fn tm_to_datetime(mut tm: Tm) -> DateTime<Local> {
+    if tm.tm_sec >= 60 {
+        tm.tm_nsec += (tm.tm_sec - 59) * 1_000_000_000;
+        tm.tm_sec = 59;
+    }
+
+    let date = NaiveDate::from_yo_opt(tm.tm_year + 1900, tm.tm_yday as u32 + 1)
+        .expect("invalid or out-of-range date");
+    let time = NaiveTime::from_hms_nano_opt(
+        tm.tm_hour as u32,
+        tm.tm_min as u32,
+        tm.tm_sec as u32,
+        tm.tm_nsec as u32,
+    ).expect("invalid time");
+
+    let offset = FixedOffset::east_opt(tm.tm_utcoff).unwrap();
+    DateTime::from_utc(date.and_time(time) - offset, offset)
+}
+
+/// A record specifying a time value in seconds and nanoseconds, where
+/// nanoseconds represent the offset from the given second.
+///
+/// For example a timespec of 1.2 seconds after the beginning of the epoch would
+/// be represented as {sec: 1, nsec: 200000000}.
+struct Timespec {
+    sec: i64,
+    nsec: i32,
+}
+
+impl Timespec {
+    /// Constructs a timespec representing the current time in UTC.
+    fn now() -> Timespec {
+        let st =
+            SystemTime::now().duration_since(UNIX_EPOCH).expect("system time before Unix epoch");
+        Timespec { sec: st.as_secs() as i64, nsec: st.subsec_nanos() as i32 }
+    }
+
+    /// Converts this timespec into the system's local time.
+    fn local(self) -> Tm {
+        let mut tm = Tm {
+            tm_sec: 0,
+            tm_min: 0,
+            tm_hour: 0,
+            tm_mday: 0,
+            tm_mon: 0,
+            tm_year: 0,
+            tm_wday: 0,
+            tm_yday: 0,
+            tm_isdst: 0,
+            tm_utcoff: 0,
+            tm_nsec: 0,
+        };
+        time_to_local_tm(self.sec, &mut tm);
+        tm.tm_nsec = self.nsec;
+        tm
+    }
+}
+
+/// Holds a calendar date and time broken down into its components (year, month,
+/// day, and so on), also called a broken-down time value.
+// FIXME: use c_int instead of i32?
+#[repr(C)]
+pub(super) struct Tm {
+    /// Seconds after the minute - [0, 60]
+    tm_sec: i32,
+
+    /// Minutes after the hour - [0, 59]
+    tm_min: i32,
+
+    /// Hours after midnight - [0, 23]
+    tm_hour: i32,
+
+    /// Day of the month - [1, 31]
+    tm_mday: i32,
+
+    /// Months since January - [0, 11]
+    tm_mon: i32,
+
+    /// Years since 1900
+    tm_year: i32,
+
+    /// Days since Sunday - [0, 6]. 0 = Sunday, 1 = Monday, ..., 6 = Saturday.
+    tm_wday: i32,
+
+    /// Days since January 1 - [0, 365]
+    tm_yday: i32,
+
+    /// Daylight Saving Time flag.
+    ///
+    /// This value is positive if Daylight Saving Time is in effect, zero if
+    /// Daylight Saving Time is not in effect, and negative if this information
+    /// is not available.
+    tm_isdst: i32,
+
+    /// Identifies the time zone that was used to compute this broken-down time
+    /// value, including any adjustment for Daylight Saving Time. This is the
+    /// number of seconds east of UTC. For example, for U.S. Pacific Daylight
+    /// Time, the value is `-7*60*60 = -25200`.
+    tm_utcoff: i32,
+
+    /// Nanoseconds after the second - [0, 10<sup>9</sup> - 1]
+    tm_nsec: i32,
+}
+
+fn time_to_tm(ts: i64, tm: &mut Tm) {
+    let leapyear = |year| -> bool { year % 4 == 0 && (year % 100 != 0 || year % 400 == 0) };
+
+    static YTAB: [[i64; 12]; 2] = [
+        [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31],
+        [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31],
+    ];
+
+    let mut year = 1970;
+
+    let dayclock = ts % 86400;
+    let mut dayno = ts / 86400;
+
+    tm.tm_sec = (dayclock % 60) as i32;
+    tm.tm_min = ((dayclock % 3600) / 60) as i32;
+    tm.tm_hour = (dayclock / 3600) as i32;
+    tm.tm_wday = ((dayno + 4) % 7) as i32;
+    loop {
+        let yearsize = if leapyear(year) { 366 } else { 365 };
+        if dayno >= yearsize {
+            dayno -= yearsize;
+            year += 1;
+        } else {
+            break;
+        }
+    }
+    tm.tm_year = (year - 1900) as i32;
+    tm.tm_yday = dayno as i32;
+    let mut mon = 0;
+    while dayno >= YTAB[if leapyear(year) { 1 } else { 0 }][mon] {
+        dayno -= YTAB[if leapyear(year) { 1 } else { 0 }][mon];
+        mon += 1;
+    }
+    tm.tm_mon = mon as i32;
+    tm.tm_mday = dayno as i32 + 1;
+    tm.tm_isdst = 0;
+}
+
+fn tm_to_time(tm: &Tm) -> i64 {
+    let mut y = tm.tm_year as i64 + 1900;
+    let mut m = tm.tm_mon as i64 + 1;
+    if m <= 2 {
+        y -= 1;
+        m += 12;
+    }
+    let d = tm.tm_mday as i64;
+    let h = tm.tm_hour as i64;
+    let mi = tm.tm_min as i64;
+    let s = tm.tm_sec as i64;
+    (365 * y + y / 4 - y / 100 + y / 400 + 3 * (m + 1) / 5 + 30 * m + d - 719561) * 86400
+        + 3600 * h
+        + 60 * mi
+        + s
+}
+
+pub(super) fn time_to_local_tm(sec: i64, tm: &mut Tm) {
+    // FIXME: Add timezone logic
+    time_to_tm(sec, tm);
+}
+
+pub(super) fn utc_tm_to_time(tm: &Tm) -> i64 {
+    tm_to_time(tm)
+}
+
+pub(super) fn local_tm_to_time(tm: &Tm) -> i64 {
+    // FIXME: Add timezone logic
+    tm_to_time(tm)
+}

javascript-engine/external/chrono/src/offset/local/tz_info/mod.rs

@@ -0,0 +1,131 @@
+#![deny(missing_docs)]
+#![allow(dead_code)]
+#![warn(unreachable_pub)]
+
+use std::num::ParseIntError;
+use std::str::Utf8Error;
+use std::time::SystemTimeError;
+use std::{error, fmt, io};
+
+mod timezone;
+pub(crate) use timezone::TimeZone;
+
+mod parser;
+mod rule;
+
+/// Unified error type for everything in the crate
+#[derive(Debug)]
+pub(crate) enum Error {
+    /// Date time error
+    DateTime(&'static str),
+    /// Local time type search error
+    FindLocalTimeType(&'static str),
+    /// Local time type error
+    LocalTimeType(&'static str),
+    /// Invalid slice for integer conversion
+    InvalidSlice(&'static str),
+    /// Invalid Tzif file
+    InvalidTzFile(&'static str),
+    /// Invalid TZ string
+    InvalidTzString(&'static str),
+    /// I/O error
+    Io(io::Error),
+    /// Out of range error
+    OutOfRange(&'static str),
+    /// Integer parsing error
+    ParseInt(ParseIntError),
+    /// Date time projection error
+    ProjectDateTime(&'static str),
+    /// System time error
+    SystemTime(SystemTimeError),
+    /// Time zone error
+    TimeZone(&'static str),
+    /// Transition rule error
+    TransitionRule(&'static str),
+    /// Unsupported Tzif file
+    UnsupportedTzFile(&'static str),
+    /// Unsupported TZ string
+    UnsupportedTzString(&'static str),
+    /// UTF-8 error
+    Utf8(Utf8Error),
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        use Error::*;
+        match self {
+            DateTime(error) => write!(f, "invalid date time: {}", error),
+            FindLocalTimeType(error) => error.fmt(f),
+            LocalTimeType(error) => write!(f, "invalid local time type: {}", error),
+            InvalidSlice(error) => error.fmt(f),
+            InvalidTzString(error) => write!(f, "invalid TZ string: {}", error),
+            InvalidTzFile(error) => error.fmt(f),
+            Io(error) => error.fmt(f),
+            OutOfRange(error) => error.fmt(f),
+            ParseInt(error) => error.fmt(f),
+            ProjectDateTime(error) => error.fmt(f),
+            SystemTime(error) => error.fmt(f),
+            TransitionRule(error) => write!(f, "invalid transition rule: {}", error),
+            TimeZone(error) => write!(f, "invalid time zone: {}", error),
+            UnsupportedTzFile(error) => error.fmt(f),
+            UnsupportedTzString(error) => write!(f, "unsupported TZ string: {}", error),
+            Utf8(error) => error.fmt(f),
+        }
+    }
+}
+
+impl error::Error for Error {}
+
+impl From<io::Error> for Error {
+    fn from(error: io::Error) -> Self {
+        Error::Io(error)
+    }
+}
+
+impl From<ParseIntError> for Error {
+    fn from(error: ParseIntError) -> Self {
+        Error::ParseInt(error)
+    }
+}
+
+impl From<SystemTimeError> for Error {
+    fn from(error: SystemTimeError) -> Self {
+        Error::SystemTime(error)
+    }
+}
+
+impl From<Utf8Error> for Error {
+    fn from(error: Utf8Error) -> Self {
+        Error::Utf8(error)
+    }
+}
+
+// MSRV: 1.38
+#[inline]
+fn rem_euclid(v: i64, rhs: i64) -> i64 {
+    let r = v % rhs;
+    if r < 0 {
+        if rhs < 0 {
+            r - rhs
+        } else {
+            r + rhs
+        }
+    } else {
+        r
+    }
+}
+
+/// Number of hours in one day
+const HOURS_PER_DAY: i64 = 24;
+/// Number of seconds in one hour
+const SECONDS_PER_HOUR: i64 = 3600;
+/// Number of seconds in one day
+const SECONDS_PER_DAY: i64 = SECONDS_PER_HOUR * HOURS_PER_DAY;
+/// Number of days in one week
+const DAYS_PER_WEEK: i64 = 7;
+
+/// Month days in a normal year
+const DAY_IN_MONTHS_NORMAL_YEAR: [i64; 12] = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
+/// Cumulated month days in a normal year
+const CUMUL_DAY_IN_MONTHS_NORMAL_YEAR: [i64; 12] =
+    [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334];

javascript-engine/external/chrono/src/offset/local/tz_info/parser.rs

@@ -0,0 +1,334 @@
+use std::io::{self, ErrorKind};
+use std::iter;
+use std::num::ParseIntError;
+use std::str::{self, FromStr};
+
+use super::rule::TransitionRule;
+use super::timezone::{LeapSecond, LocalTimeType, TimeZone, Transition};
+use super::Error;
+
+#[allow(clippy::map_clone)] // MSRV: 1.36
+pub(super) fn parse(bytes: &[u8]) -> Result<TimeZone, Error> {
+    let mut cursor = Cursor::new(bytes);
+    let state = State::new(&mut cursor, true)?;
+    let (state, footer) = match state.header.version {
+        Version::V1 => match cursor.is_empty() {
+            true => (state, None),
+            false => {
+                return Err(Error::InvalidTzFile("remaining data after end of TZif v1 data block"))
+            }
+        },
+        Version::V2 | Version::V3 => {
+            let state = State::new(&mut cursor, false)?;
+            (state, Some(cursor.remaining()))
+        }
+    };
+
+    let mut transitions = Vec::with_capacity(state.header.transition_count);
+    for (arr_time, &local_time_type_index) in
+        state.transition_times.chunks_exact(state.time_size).zip(state.transition_types)
+    {
+        let unix_leap_time =
+            state.parse_time(&arr_time[0..state.time_size], state.header.version)?;
+        let local_time_type_index = local_time_type_index as usize;
+        transitions.push(Transition::new(unix_leap_time, local_time_type_index));
+    }
+
+    let mut local_time_types = Vec::with_capacity(state.header.type_count);
+    for arr in state.local_time_types.chunks_exact(6) {
+        let ut_offset = read_be_i32(&arr[..4])?;
+
+        let is_dst = match arr[4] {
+            0 => false,
+            1 => true,
+            _ => return Err(Error::InvalidTzFile("invalid DST indicator")),
+        };
+
+        let char_index = arr[5] as usize;
+        if char_index >= state.header.char_count {
+            return Err(Error::InvalidTzFile("invalid time zone name char index"));
+        }
+
+        let position = match state.names[char_index..].iter().position(|&c| c == b'\0') {
+            Some(position) => position,
+            None => return Err(Error::InvalidTzFile("invalid time zone name char index")),
+        };
+
+        let name = &state.names[char_index..char_index + position];
+        let name = if !name.is_empty() { Some(name) } else { None };
+        local_time_types.push(LocalTimeType::new(ut_offset, is_dst, name)?);
+    }
+
+    let mut leap_seconds = Vec::with_capacity(state.header.leap_count);
+    for arr in state.leap_seconds.chunks_exact(state.time_size + 4) {
+        let unix_leap_time = state.parse_time(&arr[0..state.time_size], state.header.version)?;
+        let correction = read_be_i32(&arr[state.time_size..state.time_size + 4])?;
+        leap_seconds.push(LeapSecond::new(unix_leap_time, correction));
+    }
+
+    let std_walls_iter = state.std_walls.iter().map(|&i| i).chain(iter::repeat(0));
+    let ut_locals_iter = state.ut_locals.iter().map(|&i| i).chain(iter::repeat(0));
+    if std_walls_iter.zip(ut_locals_iter).take(state.header.type_count).any(|pair| pair == (0, 1)) {
+        return Err(Error::InvalidTzFile(
+            "invalid couple of standard/wall and UT/local indicators",
+        ));
+    }
+
+    let extra_rule = match footer {
+        Some(footer) => {
+            let footer = str::from_utf8(footer)?;
+            if !(footer.starts_with('\n') && footer.ends_with('\n')) {
+                return Err(Error::InvalidTzFile("invalid footer"));
+            }
+
+            let tz_string = footer.trim_matches(|c: char| c.is_ascii_whitespace());
+            if tz_string.starts_with(':') || tz_string.contains('\0') {
+                return Err(Error::InvalidTzFile("invalid footer"));
+            }
+
+            match tz_string.is_empty() {
+                true => None,
+                false => Some(TransitionRule::from_tz_string(
+                    tz_string.as_bytes(),
+                    state.header.version == Version::V3,
+                )?),
+            }
+        }
+        None => None,
+    };
+
+    TimeZone::new(transitions, local_time_types, leap_seconds, extra_rule)
+}
+
+/// TZif data blocks
+struct State<'a> {
+    header: Header,
+    /// Time size in bytes
+    time_size: usize,
+    /// Transition times data block
+    transition_times: &'a [u8],
+    /// Transition types data block
+    transition_types: &'a [u8],
+    /// Local time types data block
+    local_time_types: &'a [u8],
+    /// Time zone names data block
+    names: &'a [u8],
+    /// Leap seconds data block
+    leap_seconds: &'a [u8],
+    /// UT/local indicators data block
+    std_walls: &'a [u8],
+    /// Standard/wall indicators data block
+    ut_locals: &'a [u8],
+}
+
+impl<'a> State<'a> {
+    /// Read TZif data blocks
+    fn new(cursor: &mut Cursor<'a>, first: bool) -> Result<Self, Error> {
+        let header = Header::new(cursor)?;
+        let time_size = match first {
+            true => 4, // We always parse V1 first
+            false => 8,
+        };
+
+        Ok(Self {
+            time_size,
+            transition_times: cursor.read_exact(header.transition_count * time_size)?,
+            transition_types: cursor.read_exact(header.transition_count)?,
+            local_time_types: cursor.read_exact(header.type_count * 6)?,
+            names: cursor.read_exact(header.char_count)?,
+            leap_seconds: cursor.read_exact(header.leap_count * (time_size + 4))?,
+            std_walls: cursor.read_exact(header.std_wall_count)?,
+            ut_locals: cursor.read_exact(header.ut_local_count)?,
+            header,
+        })
+    }
+
+    /// Parse time values
+    fn parse_time(&self, arr: &[u8], version: Version) -> Result<i64, Error> {
+        match version {
+            Version::V1 => Ok(read_be_i32(&arr[..4])?.into()),
+            Version::V2 | Version::V3 => read_be_i64(arr),
+        }
+    }
+}
+
+/// TZif header
+#[derive(Debug)]
+struct Header {
+    /// TZif version
+    version: Version,
+    /// Number of UT/local indicators
+    ut_local_count: usize,
+    /// Number of standard/wall indicators
+    std_wall_count: usize,
+    /// Number of leap-second records
+    leap_count: usize,
+    /// Number of transition times
+    transition_count: usize,
+    /// Number of local time type records
+    type_count: usize,
+    /// Number of time zone names bytes
+    char_count: usize,
+}
+
+impl Header {
+    fn new(cursor: &mut Cursor) -> Result<Self, Error> {
+        let magic = cursor.read_exact(4)?;
+        if magic != *b"TZif" {
+            return Err(Error::InvalidTzFile("invalid magic number"));
+        }
+
+        let version = match cursor.read_exact(1)? {
+            [0x00] => Version::V1,
+            [0x32] => Version::V2,
+            [0x33] => Version::V3,
+            _ => return Err(Error::UnsupportedTzFile("unsupported TZif version")),
+        };
+
+        cursor.read_exact(15)?;
+        let ut_local_count = cursor.read_be_u32()?;
+        let std_wall_count = cursor.read_be_u32()?;
+        let leap_count = cursor.read_be_u32()?;
+        let transition_count = cursor.read_be_u32()?;
+        let type_count = cursor.read_be_u32()?;
+        let char_count = cursor.read_be_u32()?;
+
+        if !(type_count != 0
+            && char_count != 0
+            && (ut_local_count == 0 || ut_local_count == type_count)
+            && (std_wall_count == 0 || std_wall_count == type_count))
+        {
+            return Err(Error::InvalidTzFile("invalid header"));
+        }
+
+        Ok(Self {
+            version,
+            ut_local_count: ut_local_count as usize,
+            std_wall_count: std_wall_count as usize,
+            leap_count: leap_count as usize,
+            transition_count: transition_count as usize,
+            type_count: type_count as usize,
+            char_count: char_count as usize,
+        })
+    }
+}
+
+/// A `Cursor` contains a slice of a buffer and a read count.
+#[derive(Debug, Eq, PartialEq)]
+pub(crate) struct Cursor<'a> {
+    /// Slice representing the remaining data to be read
+    remaining: &'a [u8],
+    /// Number of already read bytes
+    read_count: usize,
+}
+
+impl<'a> Cursor<'a> {
+    /// Construct a new `Cursor` from remaining data
+    pub(crate) fn new(remaining: &'a [u8]) -> Self {
+        Self { remaining, read_count: 0 }
+    }
+
+    pub(crate) fn peek(&self) -> Option<&u8> {
+        self.remaining().first()
+    }
+
+    /// Returns remaining data
+    pub(crate) fn remaining(&self) -> &'a [u8] {
+        self.remaining
+    }
+
+    /// Returns `true` if data is remaining
+    pub(crate) fn is_empty(&self) -> bool {
+        self.remaining.is_empty()
+    }
+
+    pub(crate) fn read_be_u32(&mut self) -> Result<u32, Error> {
+        let mut buf = [0; 4];
+        buf.copy_from_slice(self.read_exact(4)?);
+        Ok(u32::from_be_bytes(buf))
+    }
+
+    /// Read exactly `count` bytes, reducing remaining data and incrementing read count
+    pub(crate) fn read_exact(&mut self, count: usize) -> Result<&'a [u8], io::Error> {
+        match (self.remaining.get(..count), self.remaining.get(count..)) {
+            (Some(result), Some(remaining)) => {
+                self.remaining = remaining;
+                self.read_count += count;
+                Ok(result)
+            }
+            _ => Err(io::Error::from(ErrorKind::UnexpectedEof)),
+        }
+    }
+
+    /// Read bytes and compare them to the provided tag
+    pub(crate) fn read_tag(&mut self, tag: &[u8]) -> Result<(), io::Error> {
+        if self.read_exact(tag.len())? == tag {
+            Ok(())
+        } else {
+            Err(io::Error::from(ErrorKind::InvalidData))
+        }
+    }
+
+    /// Read bytes if the remaining data is prefixed by the provided tag
+    pub(crate) fn read_optional_tag(&mut self, tag: &[u8]) -> Result<bool, io::Error> {
+        if self.remaining.starts_with(tag) {
+            self.read_exact(tag.len())?;
+            Ok(true)
+        } else {
+            Ok(false)
+        }
+    }
+
+    /// Read bytes as long as the provided predicate is true
+    pub(crate) fn read_while<F: Fn(&u8) -> bool>(&mut self, f: F) -> Result<&'a [u8], io::Error> {
+        match self.remaining.iter().position(|x| !f(x)) {
+            None => self.read_exact(self.remaining.len()),
+            Some(position) => self.read_exact(position),
+        }
+    }
+
+    // Parse an integer out of the ASCII digits
+    pub(crate) fn read_int<T: FromStr<Err = ParseIntError>>(&mut self) -> Result<T, Error> {
+        let bytes = self.read_while(u8::is_ascii_digit)?;
+        Ok(str::from_utf8(bytes)?.parse()?)
+    }
+
+    /// Read bytes until the provided predicate is true
+    pub(crate) fn read_until<F: Fn(&u8) -> bool>(&mut self, f: F) -> Result<&'a [u8], io::Error> {
+        match self.remaining.iter().position(f) {
+            None => self.read_exact(self.remaining.len()),
+            Some(position) => self.read_exact(position),
+        }
+    }
+}
+
+pub(crate) fn read_be_i32(bytes: &[u8]) -> Result<i32, Error> {
+    if bytes.len() != 4 {
+        return Err(Error::InvalidSlice("too short for i32"));
+    }
+
+    let mut buf = [0; 4];
+    buf.copy_from_slice(bytes);
+    Ok(i32::from_be_bytes(buf))
+}
+
+pub(crate) fn read_be_i64(bytes: &[u8]) -> Result<i64, Error> {
+    if bytes.len() != 8 {
+        return Err(Error::InvalidSlice("too short for i64"));
+    }
+
+    let mut buf = [0; 8];
+    buf.copy_from_slice(bytes);
+    Ok(i64::from_be_bytes(buf))
+}
+
+/// TZif version
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+enum Version {
+    /// Version 1
+    V1,
+    /// Version 2
+    V2,
+    /// Version 3
+    V3,
+}

javascript-engine/external/chrono/src/offset/local/tz_info/timezone.rs

@@ -0,0 +1,904 @@
+//! Types related to a time zone.
+
+use std::fs::{self, File};
+use std::io::{self, Read};
+use std::path::{Path, PathBuf};
+use std::{cmp::Ordering, fmt, str};
+
+use super::rule::{AlternateTime, TransitionRule};
+use super::{parser, Error, DAYS_PER_WEEK, SECONDS_PER_DAY};
+
+/// Time zone
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub(crate) struct TimeZone {
+    /// List of transitions
+    transitions: Vec<Transition>,
+    /// List of local time types (cannot be empty)
+    local_time_types: Vec<LocalTimeType>,
+    /// List of leap seconds
+    leap_seconds: Vec<LeapSecond>,
+    /// Extra transition rule applicable after the last transition
+    extra_rule: Option<TransitionRule>,
+}
+
+impl TimeZone {
+    /// Returns local time zone.
+    ///
+    /// This method in not supported on non-UNIX platforms, and returns the UTC time zone instead.
+    ///
+    pub(crate) fn local(env_tz: Option<&str>) -> Result<Self, Error> {
+        match env_tz {
+            Some(tz) => Self::from_posix_tz(tz),
+            None => Self::from_posix_tz("localtime"),
+        }
+    }
+
+    /// Construct a time zone from a POSIX TZ string, as described in [the POSIX documentation of the `TZ` environment variable](https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html).
+    fn from_posix_tz(tz_string: &str) -> Result<Self, Error> {
+        if tz_string.is_empty() {
+            return Err(Error::InvalidTzString("empty TZ string"));
+        }
+
+        if tz_string == "localtime" {
+            return Self::from_tz_data(&fs::read("/etc/localtime")?);
+        }
+
+        let mut chars = tz_string.chars();
+        if chars.next() == Some(':') {
+            return Self::from_file(&mut find_tz_file(chars.as_str())?);
+        }
+
+        if let Ok(mut file) = find_tz_file(tz_string) {
+            return Self::from_file(&mut file);
+        }
+
+        // TZ string extensions are not allowed
+        let tz_string = tz_string.trim_matches(|c: char| c.is_ascii_whitespace());
+        let rule = TransitionRule::from_tz_string(tz_string.as_bytes(), false)?;
+        Self::new(
+            vec![],
+            match rule {
+                TransitionRule::Fixed(local_time_type) => vec![local_time_type],
+                TransitionRule::Alternate(AlternateTime { std, dst, .. }) => vec![std, dst],
+            },
+            vec![],
+            Some(rule),
+        )
+    }
+
+    /// Construct a time zone
+    pub(super) fn new(
+        transitions: Vec<Transition>,
+        local_time_types: Vec<LocalTimeType>,
+        leap_seconds: Vec<LeapSecond>,
+        extra_rule: Option<TransitionRule>,
+    ) -> Result<Self, Error> {
+        let new = Self { transitions, local_time_types, leap_seconds, extra_rule };
+        new.as_ref().validate()?;
+        Ok(new)
+    }
+
+    /// Construct a time zone from the contents of a time zone file
+    fn from_file(file: &mut File) -> Result<Self, Error> {
+        let mut bytes = Vec::new();
+        file.read_to_end(&mut bytes)?;
+        Self::from_tz_data(&bytes)
+    }
+
+    /// Construct a time zone from the contents of a time zone file
+    ///
+    /// Parse TZif data as described in [RFC 8536](https://datatracker.ietf.org/doc/html/rfc8536).
+    pub(crate) fn from_tz_data(bytes: &[u8]) -> Result<Self, Error> {
+        parser::parse(bytes)
+    }
+
+    /// Construct a time zone with the specified UTC offset in seconds
+    fn fixed(ut_offset: i32) -> Result<Self, Error> {
+        Ok(Self {
+            transitions: Vec::new(),
+            local_time_types: vec![LocalTimeType::with_offset(ut_offset)?],
+            leap_seconds: Vec::new(),
+            extra_rule: None,
+        })
+    }
+
+    /// Construct the time zone associated to UTC
+    pub(crate) fn utc() -> Self {
+        Self {
+            transitions: Vec::new(),
+            local_time_types: vec![LocalTimeType::UTC],
+            leap_seconds: Vec::new(),
+            extra_rule: None,
+        }
+    }
+
+    /// Find the local time type associated to the time zone at the specified Unix time in seconds
+    pub(crate) fn find_local_time_type(&self, unix_time: i64) -> Result<&LocalTimeType, Error> {
+        self.as_ref().find_local_time_type(unix_time)
+    }
+
+    // should we pass NaiveDateTime all the way through to this fn?
+    pub(crate) fn find_local_time_type_from_local(
+        &self,
+        local_time: i64,
+        year: i32,
+    ) -> Result<crate::LocalResult<LocalTimeType>, Error> {
+        self.as_ref().find_local_time_type_from_local(local_time, year)
+    }
+
+    /// Returns a reference to the time zone
+    fn as_ref(&self) -> TimeZoneRef {
+        TimeZoneRef {
+            transitions: &self.transitions,
+            local_time_types: &self.local_time_types,
+            leap_seconds: &self.leap_seconds,
+            extra_rule: &self.extra_rule,
+        }
+    }
+}
+
+/// Reference to a time zone
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub(crate) struct TimeZoneRef<'a> {
+    /// List of transitions
+    transitions: &'a [Transition],
+    /// List of local time types (cannot be empty)
+    local_time_types: &'a [LocalTimeType],
+    /// List of leap seconds
+    leap_seconds: &'a [LeapSecond],
+    /// Extra transition rule applicable after the last transition
+    extra_rule: &'a Option<TransitionRule>,
+}
+
+impl<'a> TimeZoneRef<'a> {
+    /// Find the local time type associated to the time zone at the specified Unix time in seconds
+    pub(crate) fn find_local_time_type(&self, unix_time: i64) -> Result<&'a LocalTimeType, Error> {
+        let extra_rule = match self.transitions.last() {
+            None => match self.extra_rule {
+                Some(extra_rule) => extra_rule,
+                None => return Ok(&self.local_time_types[0]),
+            },
+            Some(last_transition) => {
+                let unix_leap_time = match self.unix_time_to_unix_leap_time(unix_time) {
+                    Ok(unix_leap_time) => unix_leap_time,
+                    Err(Error::OutOfRange(error)) => return Err(Error::FindLocalTimeType(error)),
+                    Err(err) => return Err(err),
+                };
+
+                if unix_leap_time >= last_transition.unix_leap_time {
+                    match self.extra_rule {
+                        Some(extra_rule) => extra_rule,
+                        None => {
+                            return Err(Error::FindLocalTimeType(
+                                "no local time type is available for the specified timestamp",
+                            ))
+                        }
+                    }
+                } else {
+                    let index = match self
+                        .transitions
+                        .binary_search_by_key(&unix_leap_time, Transition::unix_leap_time)
+                    {
+                        Ok(x) => x + 1,
+                        Err(x) => x,
+                    };
+
+                    let local_time_type_index = if index > 0 {
+                        self.transitions[index - 1].local_time_type_index
+                    } else {
+                        0
+                    };
+                    return Ok(&self.local_time_types[local_time_type_index]);
+                }
+            }
+        };
+
+        match extra_rule.find_local_time_type(unix_time) {
+            Ok(local_time_type) => Ok(local_time_type),
+            Err(Error::OutOfRange(error)) => Err(Error::FindLocalTimeType(error)),
+            err => err,
+        }
+    }
+
+    pub(crate) fn find_local_time_type_from_local(
+        &self,
+        local_time: i64,
+        year: i32,
+    ) -> Result<crate::LocalResult<LocalTimeType>, Error> {
+        // #TODO: this is wrong as we need 'local_time_to_local_leap_time ?
+        // but ... does the local time even include leap seconds ??
+        // let unix_leap_time = match self.unix_time_to_unix_leap_time(local_time) {
+        //     Ok(unix_leap_time) => unix_leap_time,
+        //     Err(Error::OutOfRange(error)) => return Err(Error::FindLocalTimeType(error)),
+        //     Err(err) => return Err(err),
+        // };
+        let local_leap_time = local_time;
+
+        // if we have at least one transition,
+        // we must check _all_ of them, incase of any Overlapping (LocalResult::Ambiguous) or Skipping (LocalResult::None) transitions
+        if !self.transitions.is_empty() {
+            let mut prev = Some(self.local_time_types[0]);
+
+            for transition in self.transitions {
+                let after_ltt = self.local_time_types[transition.local_time_type_index];
+
+                // the end and start here refers to where the time starts prior to the transition
+                // and where it ends up after. not the temporal relationship.
+                let transition_end = transition.unix_leap_time + i64::from(after_ltt.ut_offset);
+                let transition_start =
+                    transition.unix_leap_time + i64::from(prev.unwrap().ut_offset);
+
+                match transition_start.cmp(&transition_end) {
+                    Ordering::Greater => {
+                        // bakwards transition, eg from DST to regular
+                        // this means a given local time could have one of two possible offsets
+                        if local_leap_time < transition_end {
+                            return Ok(crate::LocalResult::Single(prev.unwrap()));
+                        } else if local_leap_time >= transition_end
+                            && local_leap_time <= transition_start
+                        {
+                            if prev.unwrap().ut_offset < after_ltt.ut_offset {
+                                return Ok(crate::LocalResult::Ambiguous(prev.unwrap(), after_ltt));
+                            } else {
+                                return Ok(crate::LocalResult::Ambiguous(after_ltt, prev.unwrap()));
+                            }
+                        }
+                    }
+                    Ordering::Equal => {
+                        // should this ever happen? presumably we have to handle it anyway.
+                        if local_leap_time < transition_start {
+                            return Ok(crate::LocalResult::Single(prev.unwrap()));
+                        } else if local_leap_time == transition_end {
+                            if prev.unwrap().ut_offset < after_ltt.ut_offset {
+                                return Ok(crate::LocalResult::Ambiguous(prev.unwrap(), after_ltt));
+                            } else {
+                                return Ok(crate::LocalResult::Ambiguous(after_ltt, prev.unwrap()));
+                            }
+                        }
+                    }
+                    Ordering::Less => {
+                        // forwards transition, eg from regular to DST
+                        // this means that times that are skipped are invalid local times
+                        if local_leap_time <= transition_start {
+                            return Ok(crate::LocalResult::Single(prev.unwrap()));
+                        } else if local_leap_time < transition_end {
+                            return Ok(crate::LocalResult::None);
+                        } else if local_leap_time == transition_end {
+                            return Ok(crate::LocalResult::Single(after_ltt));
+                        }
+                    }
+                }
+
+                // try the next transition, we are fully after this one
+                prev = Some(after_ltt);
+            }
+        };
+
+        if let Some(extra_rule) = self.extra_rule {
+            match extra_rule.find_local_time_type_from_local(local_time, year) {
+                Ok(local_time_type) => Ok(local_time_type),
+                Err(Error::OutOfRange(error)) => Err(Error::FindLocalTimeType(error)),
+                err => err,
+            }
+        } else {
+            Ok(crate::LocalResult::Single(self.local_time_types[0]))
+        }
+    }
+
+    /// Check time zone inputs
+    fn validate(&self) -> Result<(), Error> {
+        // Check local time types
+        let local_time_types_size = self.local_time_types.len();
+        if local_time_types_size == 0 {
+            return Err(Error::TimeZone("list of local time types must not be empty"));
+        }
+
+        // Check transitions
+        let mut i_transition = 0;
+        while i_transition < self.transitions.len() {
+            if self.transitions[i_transition].local_time_type_index >= local_time_types_size {
+                return Err(Error::TimeZone("invalid local time type index"));
+            }
+
+            if i_transition + 1 < self.transitions.len()
+                && self.transitions[i_transition].unix_leap_time
+                    >= self.transitions[i_transition + 1].unix_leap_time
+            {
+                return Err(Error::TimeZone("invalid transition"));
+            }
+
+            i_transition += 1;
+        }
+
+        // Check leap seconds
+        if !(self.leap_seconds.is_empty()
+            || self.leap_seconds[0].unix_leap_time >= 0
+                && saturating_abs(self.leap_seconds[0].correction) == 1)
+        {
+            return Err(Error::TimeZone("invalid leap second"));
+        }
+
+        let min_interval = SECONDS_PER_28_DAYS - 1;
+
+        let mut i_leap_second = 0;
+        while i_leap_second < self.leap_seconds.len() {
+            if i_leap_second + 1 < self.leap_seconds.len() {
+                let x0 = &self.leap_seconds[i_leap_second];
+                let x1 = &self.leap_seconds[i_leap_second + 1];
+
+                let diff_unix_leap_time = x1.unix_leap_time.saturating_sub(x0.unix_leap_time);
+                let abs_diff_correction =
+                    saturating_abs(x1.correction.saturating_sub(x0.correction));
+
+                if !(diff_unix_leap_time >= min_interval && abs_diff_correction == 1) {
+                    return Err(Error::TimeZone("invalid leap second"));
+                }
+            }
+            i_leap_second += 1;
+        }
+
+        // Check extra rule
+        let (extra_rule, last_transition) = match (&self.extra_rule, self.transitions.last()) {
+            (Some(rule), Some(trans)) => (rule, trans),
+            _ => return Ok(()),
+        };
+
+        let last_local_time_type = &self.local_time_types[last_transition.local_time_type_index];
+        let unix_time = match self.unix_leap_time_to_unix_time(last_transition.unix_leap_time) {
+            Ok(unix_time) => unix_time,
+            Err(Error::OutOfRange(error)) => return Err(Error::TimeZone(error)),
+            Err(err) => return Err(err),
+        };
+
+        let rule_local_time_type = match extra_rule.find_local_time_type(unix_time) {
+            Ok(rule_local_time_type) => rule_local_time_type,
+            Err(Error::OutOfRange(error)) => return Err(Error::TimeZone(error)),
+            Err(err) => return Err(err),
+        };
+
+        let check = last_local_time_type.ut_offset == rule_local_time_type.ut_offset
+            && last_local_time_type.is_dst == rule_local_time_type.is_dst
+            && match (&last_local_time_type.name, &rule_local_time_type.name) {
+                (Some(x), Some(y)) => x.equal(y),
+                (None, None) => true,
+                _ => false,
+            };
+
+        if !check {
+            return Err(Error::TimeZone(
+                "extra transition rule is inconsistent with the last transition",
+            ));
+        }
+
+        Ok(())
+    }
+
+    /// Convert Unix time to Unix leap time, from the list of leap seconds in a time zone
+    fn unix_time_to_unix_leap_time(&self, unix_time: i64) -> Result<i64, Error> {
+        let mut unix_leap_time = unix_time;
+
+        let mut i = 0;
+        while i < self.leap_seconds.len() {
+            let leap_second = &self.leap_seconds[i];
+
+            if unix_leap_time < leap_second.unix_leap_time {
+                break;
+            }
+
+            unix_leap_time = match unix_time.checked_add(leap_second.correction as i64) {
+                Some(unix_leap_time) => unix_leap_time,
+                None => return Err(Error::OutOfRange("out of range operation")),
+            };
+
+            i += 1;
+        }
+
+        Ok(unix_leap_time)
+    }
+
+    /// Convert Unix leap time to Unix time, from the list of leap seconds in a time zone
+    fn unix_leap_time_to_unix_time(&self, unix_leap_time: i64) -> Result<i64, Error> {
+        if unix_leap_time == i64::min_value() {
+            return Err(Error::OutOfRange("out of range operation"));
+        }
+
+        let index = match self
+            .leap_seconds
+            .binary_search_by_key(&(unix_leap_time - 1), LeapSecond::unix_leap_time)
+        {
+            Ok(x) => x + 1,
+            Err(x) => x,
+        };
+
+        let correction = if index > 0 { self.leap_seconds[index - 1].correction } else { 0 };
+
+        match unix_leap_time.checked_sub(correction as i64) {
+            Some(unix_time) => Ok(unix_time),
+            None => Err(Error::OutOfRange("out of range operation")),
+        }
+    }
+
+    /// The UTC time zone
+    const UTC: TimeZoneRef<'static> = TimeZoneRef {
+        transitions: &[],
+        local_time_types: &[LocalTimeType::UTC],
+        leap_seconds: &[],
+        extra_rule: &None,
+    };
+}
+
+/// Transition of a TZif file
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub(super) struct Transition {
+    /// Unix leap time
+    unix_leap_time: i64,
+    /// Index specifying the local time type of the transition
+    local_time_type_index: usize,
+}
+
+impl Transition {
+    /// Construct a TZif file transition
+    pub(super) fn new(unix_leap_time: i64, local_time_type_index: usize) -> Self {
+        Self { unix_leap_time, local_time_type_index }
+    }
+
+    /// Returns Unix leap time
+    fn unix_leap_time(&self) -> i64 {
+        self.unix_leap_time
+    }
+}
+
+/// Leap second of a TZif file
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub(super) struct LeapSecond {
+    /// Unix leap time
+    unix_leap_time: i64,
+    /// Leap second correction
+    correction: i32,
+}
+
+impl LeapSecond {
+    /// Construct a TZif file leap second
+    pub(super) fn new(unix_leap_time: i64, correction: i32) -> Self {
+        Self { unix_leap_time, correction }
+    }
+
+    /// Returns Unix leap time
+    fn unix_leap_time(&self) -> i64 {
+        self.unix_leap_time
+    }
+}
+
+/// ASCII-encoded fixed-capacity string, used for storing time zone names
+#[derive(Copy, Clone, Eq, PartialEq)]
+struct TimeZoneName {
+    /// Length-prefixed string buffer
+    bytes: [u8; 8],
+}
+
+impl TimeZoneName {
+    /// Construct a time zone name
+    fn new(input: &[u8]) -> Result<Self, Error> {
+        let len = input.len();
+
+        if !(3..=7).contains(&len) {
+            return Err(Error::LocalTimeType(
+                "time zone name must have between 3 and 7 characters",
+            ));
+        }
+
+        let mut bytes = [0; 8];
+        bytes[0] = input.len() as u8;
+
+        let mut i = 0;
+        while i < len {
+            let b = input[i];
+            match b {
+                b'0'..=b'9' | b'A'..=b'Z' | b'a'..=b'z' | b'+' | b'-' => {}
+                _ => return Err(Error::LocalTimeType("invalid characters in time zone name")),
+            }
+
+            bytes[i + 1] = b;
+            i += 1;
+        }
+
+        Ok(Self { bytes })
+    }
+
+    /// Returns time zone name as a byte slice
+    fn as_bytes(&self) -> &[u8] {
+        match self.bytes[0] {
+            3 => &self.bytes[1..4],
+            4 => &self.bytes[1..5],
+            5 => &self.bytes[1..6],
+            6 => &self.bytes[1..7],
+            7 => &self.bytes[1..8],
+            _ => unreachable!(),
+        }
+    }
+
+    /// Check if two time zone names are equal
+    fn equal(&self, other: &Self) -> bool {
+        self.bytes == other.bytes
+    }
+}
+
+impl AsRef<str> for TimeZoneName {
+    fn as_ref(&self) -> &str {
+        // SAFETY: ASCII is valid UTF-8
+        unsafe { str::from_utf8_unchecked(self.as_bytes()) }
+    }
+}
+
+impl fmt::Debug for TimeZoneName {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        self.as_ref().fmt(f)
+    }
+}
+
+/// Local time type associated to a time zone
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub(crate) struct LocalTimeType {
+    /// Offset from UTC in seconds
+    pub(super) ut_offset: i32,
+    /// Daylight Saving Time indicator
+    is_dst: bool,
+    /// Time zone name
+    name: Option<TimeZoneName>,
+}
+
+impl LocalTimeType {
+    /// Construct a local time type
+    pub(super) fn new(ut_offset: i32, is_dst: bool, name: Option<&[u8]>) -> Result<Self, Error> {
+        if ut_offset == i32::min_value() {
+            return Err(Error::LocalTimeType("invalid UTC offset"));
+        }
+
+        let name = match name {
+            Some(name) => TimeZoneName::new(name)?,
+            None => return Ok(Self { ut_offset, is_dst, name: None }),
+        };
+
+        Ok(Self { ut_offset, is_dst, name: Some(name) })
+    }
+
+    /// Construct a local time type with the specified UTC offset in seconds
+    pub(super) fn with_offset(ut_offset: i32) -> Result<Self, Error> {
+        if ut_offset == i32::min_value() {
+            return Err(Error::LocalTimeType("invalid UTC offset"));
+        }
+
+        Ok(Self { ut_offset, is_dst: false, name: None })
+    }
+
+    /// Returns offset from UTC in seconds
+    pub(crate) fn offset(&self) -> i32 {
+        self.ut_offset
+    }
+
+    /// Returns daylight saving time indicator
+    pub(super) fn is_dst(&self) -> bool {
+        self.is_dst
+    }
+
+    pub(super) const UTC: LocalTimeType = Self { ut_offset: 0, is_dst: false, name: None };
+}
+
+/// Open the TZif file corresponding to a TZ string
+fn find_tz_file(path: impl AsRef<Path>) -> Result<File, Error> {
+    // Don't check system timezone directories on non-UNIX platforms
+    #[cfg(not(unix))]
+    return Ok(File::open(path)?);
+
+    #[cfg(unix)]
+    {
+        let path = path.as_ref();
+        if path.is_absolute() {
+            return Ok(File::open(path)?);
+        }
+
+        for folder in &ZONE_INFO_DIRECTORIES {
+            if let Ok(file) = File::open(PathBuf::from(folder).join(path)) {
+                return Ok(file);
+            }
+        }
+
+        Err(Error::Io(io::ErrorKind::NotFound.into()))
+    }
+}
+
+#[inline]
+fn saturating_abs(v: i32) -> i32 {
+    if v.is_positive() {
+        v
+    } else if v == i32::min_value() {
+        i32::max_value()
+    } else {
+        -v
+    }
+}
+
+// Possible system timezone directories
+#[cfg(unix)]
+const ZONE_INFO_DIRECTORIES: [&str; 3] =
+    ["/usr/share/zoneinfo", "/share/zoneinfo", "/etc/zoneinfo"];
+
+/// Number of seconds in one week
+pub(crate) const SECONDS_PER_WEEK: i64 = SECONDS_PER_DAY * DAYS_PER_WEEK;
+/// Number of seconds in 28 days
+const SECONDS_PER_28_DAYS: i64 = SECONDS_PER_DAY * 28;
+
+#[cfg(test)]
+mod tests {
+    use super::super::Error;
+    use super::{LeapSecond, LocalTimeType, TimeZone, TimeZoneName, Transition, TransitionRule};
+    use crate::matches;
+
+    #[test]
+    fn test_no_dst() -> Result<(), Error> {
+        let tz_string = b"HST10";
+        let transition_rule = TransitionRule::from_tz_string(tz_string, false)?;
+        assert_eq!(transition_rule, LocalTimeType::new(-36000, false, Some(b"HST"))?.into());
+        Ok(())
+    }
+
+    #[test]
+    fn test_error() -> Result<(), Error> {
+        assert!(matches!(
+            TransitionRule::from_tz_string(b"IST-1GMT0", false),
+            Err(Error::UnsupportedTzString(_))
+        ));
+        assert!(matches!(
+            TransitionRule::from_tz_string(b"EET-2EEST", false),
+            Err(Error::UnsupportedTzString(_))
+        ));
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_v1_file_with_leap_seconds() -> Result<(), Error> {
+        let bytes = b"TZif\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x01\0\0\0\x01\0\0\0\x1b\0\0\0\0\0\0\0\x01\0\0\0\x04\0\0\0\0\0\0UTC\0\x04\xb2\x58\0\0\0\0\x01\x05\xa4\xec\x01\0\0\0\x02\x07\x86\x1f\x82\0\0\0\x03\x09\x67\x53\x03\0\0\0\x04\x0b\x48\x86\x84\0\0\0\x05\x0d\x2b\x0b\x85\0\0\0\x06\x0f\x0c\x3f\x06\0\0\0\x07\x10\xed\x72\x87\0\0\0\x08\x12\xce\xa6\x08\0\0\0\x09\x15\x9f\xca\x89\0\0\0\x0a\x17\x80\xfe\x0a\0\0\0\x0b\x19\x62\x31\x8b\0\0\0\x0c\x1d\x25\xea\x0c\0\0\0\x0d\x21\xda\xe5\x0d\0\0\0\x0e\x25\x9e\x9d\x8e\0\0\0\x0f\x27\x7f\xd1\x0f\0\0\0\x10\x2a\x50\xf5\x90\0\0\0\x11\x2c\x32\x29\x11\0\0\0\x12\x2e\x13\x5c\x92\0\0\0\x13\x30\xe7\x24\x13\0\0\0\x14\x33\xb8\x48\x94\0\0\0\x15\x36\x8c\x10\x15\0\0\0\x16\x43\xb7\x1b\x96\0\0\0\x17\x49\x5c\x07\x97\0\0\0\x18\x4f\xef\x93\x18\0\0\0\x19\x55\x93\x2d\x99\0\0\0\x1a\x58\x68\x46\x9a\0\0\0\x1b\0\0";
+
+        let time_zone = TimeZone::from_tz_data(bytes)?;
+
+        let time_zone_result = TimeZone::new(
+            Vec::new(),
+            vec![LocalTimeType::new(0, false, Some(b"UTC"))?],
+            vec![
+                LeapSecond::new(78796800, 1),
+                LeapSecond::new(94694401, 2),
+                LeapSecond::new(126230402, 3),
+                LeapSecond::new(157766403, 4),
+                LeapSecond::new(189302404, 5),
+                LeapSecond::new(220924805, 6),
+                LeapSecond::new(252460806, 7),
+                LeapSecond::new(283996807, 8),
+                LeapSecond::new(315532808, 9),
+                LeapSecond::new(362793609, 10),
+                LeapSecond::new(394329610, 11),
+                LeapSecond::new(425865611, 12),
+                LeapSecond::new(489024012, 13),
+                LeapSecond::new(567993613, 14),
+                LeapSecond::new(631152014, 15),
+                LeapSecond::new(662688015, 16),
+                LeapSecond::new(709948816, 17),
+                LeapSecond::new(741484817, 18),
+                LeapSecond::new(773020818, 19),
+                LeapSecond::new(820454419, 20),
+                LeapSecond::new(867715220, 21),
+                LeapSecond::new(915148821, 22),
+                LeapSecond::new(1136073622, 23),
+                LeapSecond::new(1230768023, 24),
+                LeapSecond::new(1341100824, 25),
+                LeapSecond::new(1435708825, 26),
+                LeapSecond::new(1483228826, 27),
+            ],
+            None,
+        )?;
+
+        assert_eq!(time_zone, time_zone_result);
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_v2_file() -> Result<(), Error> {
+        let bytes = b"TZif2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x06\0\0\0\x06\0\0\0\0\0\0\0\x07\0\0\0\x06\0\0\0\x14\x80\0\0\0\xbb\x05\x43\x48\xbb\x21\x71\x58\xcb\x89\x3d\xc8\xd2\x23\xf4\x70\xd2\x61\x49\x38\xd5\x8d\x73\x48\x01\x02\x01\x03\x04\x01\x05\xff\xff\x6c\x02\0\0\xff\xff\x6c\x58\0\x04\xff\xff\x7a\x68\x01\x08\xff\xff\x7a\x68\x01\x0c\xff\xff\x7a\x68\x01\x10\xff\xff\x73\x60\0\x04LMT\0HST\0HDT\0HWT\0HPT\0\0\0\0\0\x01\0\0\0\0\0\x01\0TZif2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x06\0\0\0\x06\0\0\0\0\0\0\0\x07\0\0\0\x06\0\0\0\x14\xff\xff\xff\xff\x74\xe0\x70\xbe\xff\xff\xff\xff\xbb\x05\x43\x48\xff\xff\xff\xff\xbb\x21\x71\x58\xff\xff\xff\xff\xcb\x89\x3d\xc8\xff\xff\xff\xff\xd2\x23\xf4\x70\xff\xff\xff\xff\xd2\x61\x49\x38\xff\xff\xff\xff\xd5\x8d\x73\x48\x01\x02\x01\x03\x04\x01\x05\xff\xff\x6c\x02\0\0\xff\xff\x6c\x58\0\x04\xff\xff\x7a\x68\x01\x08\xff\xff\x7a\x68\x01\x0c\xff\xff\x7a\x68\x01\x10\xff\xff\x73\x60\0\x04LMT\0HST\0HDT\0HWT\0HPT\0\0\0\0\0\x01\0\0\0\0\0\x01\0\x0aHST10\x0a";
+
+        let time_zone = TimeZone::from_tz_data(bytes)?;
+
+        let time_zone_result = TimeZone::new(
+            vec![
+                Transition::new(-2334101314, 1),
+                Transition::new(-1157283000, 2),
+                Transition::new(-1155436200, 1),
+                Transition::new(-880198200, 3),
+                Transition::new(-769395600, 4),
+                Transition::new(-765376200, 1),
+                Transition::new(-712150200, 5),
+            ],
+            vec![
+                LocalTimeType::new(-37886, false, Some(b"LMT"))?,
+                LocalTimeType::new(-37800, false, Some(b"HST"))?,
+                LocalTimeType::new(-34200, true, Some(b"HDT"))?,
+                LocalTimeType::new(-34200, true, Some(b"HWT"))?,
+                LocalTimeType::new(-34200, true, Some(b"HPT"))?,
+                LocalTimeType::new(-36000, false, Some(b"HST"))?,
+            ],
+            Vec::new(),
+            Some(TransitionRule::from(LocalTimeType::new(-36000, false, Some(b"HST"))?)),
+        )?;
+
+        assert_eq!(time_zone, time_zone_result);
+
+        assert_eq!(
+            *time_zone.find_local_time_type(-1156939200)?,
+            LocalTimeType::new(-34200, true, Some(b"HDT"))?
+        );
+        assert_eq!(
+            *time_zone.find_local_time_type(1546300800)?,
+            LocalTimeType::new(-36000, false, Some(b"HST"))?
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_tz_ascii_str() -> Result<(), Error> {
+        assert!(matches!(TimeZoneName::new(b""), Err(Error::LocalTimeType(_))));
+        assert!(matches!(TimeZoneName::new(b"1"), Err(Error::LocalTimeType(_))));
+        assert!(matches!(TimeZoneName::new(b"12"), Err(Error::LocalTimeType(_))));
+        assert_eq!(TimeZoneName::new(b"123")?.as_bytes(), b"123");
+        assert_eq!(TimeZoneName::new(b"1234")?.as_bytes(), b"1234");
+        assert_eq!(TimeZoneName::new(b"12345")?.as_bytes(), b"12345");
+        assert_eq!(TimeZoneName::new(b"123456")?.as_bytes(), b"123456");
+        assert_eq!(TimeZoneName::new(b"1234567")?.as_bytes(), b"1234567");
+        assert!(matches!(TimeZoneName::new(b"12345678"), Err(Error::LocalTimeType(_))));
+        assert!(matches!(TimeZoneName::new(b"123456789"), Err(Error::LocalTimeType(_))));
+        assert!(matches!(TimeZoneName::new(b"1234567890"), Err(Error::LocalTimeType(_))));
+
+        assert!(matches!(TimeZoneName::new(b"123\0\0\0"), Err(Error::LocalTimeType(_))));
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_time_zone() -> Result<(), Error> {
+        let utc = LocalTimeType::UTC;
+        let cet = LocalTimeType::with_offset(3600)?;
+
+        let utc_local_time_types = vec![utc];
+        let fixed_extra_rule = TransitionRule::from(cet);
+
+        let time_zone_1 = TimeZone::new(vec![], utc_local_time_types.clone(), vec![], None)?;
+        let time_zone_2 =
+            TimeZone::new(vec![], utc_local_time_types.clone(), vec![], Some(fixed_extra_rule))?;
+        let time_zone_3 =
+            TimeZone::new(vec![Transition::new(0, 0)], utc_local_time_types.clone(), vec![], None)?;
+        let time_zone_4 = TimeZone::new(
+            vec![Transition::new(i32::min_value().into(), 0), Transition::new(0, 1)],
+            vec![utc, cet],
+            Vec::new(),
+            Some(fixed_extra_rule),
+        )?;
+
+        assert_eq!(*time_zone_1.find_local_time_type(0)?, utc);
+        assert_eq!(*time_zone_2.find_local_time_type(0)?, cet);
+
+        assert_eq!(*time_zone_3.find_local_time_type(-1)?, utc);
+        assert!(matches!(time_zone_3.find_local_time_type(0), Err(Error::FindLocalTimeType(_))));
+
+        assert_eq!(*time_zone_4.find_local_time_type(-1)?, utc);
+        assert_eq!(*time_zone_4.find_local_time_type(0)?, cet);
+
+        let time_zone_err = TimeZone::new(
+            vec![Transition::new(0, 0)],
+            utc_local_time_types,
+            vec![],
+            Some(fixed_extra_rule),
+        );
+        assert!(time_zone_err.is_err());
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_time_zone_from_posix_tz() -> Result<(), Error> {
+        #[cfg(unix)]
+        {
+            // if the TZ var is set, this essentially _overrides_ the
+            // time set by the localtime symlink
+            // so just ensure that ::local() acts as expected
+            // in this case
+            if let Ok(tz) = std::env::var("TZ") {
+                let time_zone_local = TimeZone::local(Some(tz.as_str()))?;
+                let time_zone_local_1 = TimeZone::from_posix_tz(&tz)?;
+                assert_eq!(time_zone_local, time_zone_local_1);
+            }
+
+            let time_zone_utc = TimeZone::from_posix_tz("UTC")?;
+            assert_eq!(time_zone_utc.find_local_time_type(0)?.offset(), 0);
+        }
+
+        assert!(TimeZone::from_posix_tz("EST5EDT,0/0,J365/25").is_err());
+        assert!(TimeZone::from_posix_tz("").is_err());
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_leap_seconds() -> Result<(), Error> {
+        let time_zone = TimeZone::new(
+            Vec::new(),
+            vec![LocalTimeType::new(0, false, Some(b"UTC"))?],
+            vec![
+                LeapSecond::new(78796800, 1),
+                LeapSecond::new(94694401, 2),
+                LeapSecond::new(126230402, 3),
+                LeapSecond::new(157766403, 4),
+                LeapSecond::new(189302404, 5),
+                LeapSecond::new(220924805, 6),
+                LeapSecond::new(252460806, 7),
+                LeapSecond::new(283996807, 8),
+                LeapSecond::new(315532808, 9),
+                LeapSecond::new(362793609, 10),
+                LeapSecond::new(394329610, 11),
+                LeapSecond::new(425865611, 12),
+                LeapSecond::new(489024012, 13),
+                LeapSecond::new(567993613, 14),
+                LeapSecond::new(631152014, 15),
+                LeapSecond::new(662688015, 16),
+                LeapSecond::new(709948816, 17),
+                LeapSecond::new(741484817, 18),
+                LeapSecond::new(773020818, 19),
+                LeapSecond::new(820454419, 20),
+                LeapSecond::new(867715220, 21),
+                LeapSecond::new(915148821, 22),
+                LeapSecond::new(1136073622, 23),
+                LeapSecond::new(1230768023, 24),
+                LeapSecond::new(1341100824, 25),
+                LeapSecond::new(1435708825, 26),
+                LeapSecond::new(1483228826, 27),
+            ],
+            None,
+        )?;
+
+        let time_zone_ref = time_zone.as_ref();
+
+        assert!(matches!(time_zone_ref.unix_leap_time_to_unix_time(1136073621), Ok(1136073599)));
+        assert!(matches!(time_zone_ref.unix_leap_time_to_unix_time(1136073622), Ok(1136073600)));
+        assert!(matches!(time_zone_ref.unix_leap_time_to_unix_time(1136073623), Ok(1136073600)));
+        assert!(matches!(time_zone_ref.unix_leap_time_to_unix_time(1136073624), Ok(1136073601)));
+
+        assert!(matches!(time_zone_ref.unix_time_to_unix_leap_time(1136073599), Ok(1136073621)));
+        assert!(matches!(time_zone_ref.unix_time_to_unix_leap_time(1136073600), Ok(1136073623)));
+        assert!(matches!(time_zone_ref.unix_time_to_unix_leap_time(1136073601), Ok(1136073624)));
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_leap_seconds_overflow() -> Result<(), Error> {
+        let time_zone_err = TimeZone::new(
+            vec![Transition::new(i64::min_value(), 0)],
+            vec![LocalTimeType::UTC],
+            vec![LeapSecond::new(0, 1)],
+            Some(TransitionRule::from(LocalTimeType::UTC)),
+        );
+        assert!(time_zone_err.is_err());
+
+        let time_zone = TimeZone::new(
+            vec![Transition::new(i64::max_value(), 0)],
+            vec![LocalTimeType::UTC],
+            vec![LeapSecond::new(0, 1)],
+            None,
+        )?;
+        assert!(matches!(
+            time_zone.find_local_time_type(i64::max_value()),
+            Err(Error::FindLocalTimeType(_))
+        ));
+
+        Ok(())
+    }
+}

javascript-engine/external/chrono/src/offset/local/unix.rs

@@ -0,0 +1,185 @@
+// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::{cell::RefCell, collections::hash_map, env, fs, hash::Hasher, time::SystemTime};
+
+use super::tz_info::TimeZone;
+use super::{DateTime, FixedOffset, Local, NaiveDateTime};
+use crate::{Datelike, LocalResult, Utc};
+
+pub(super) fn now() -> DateTime<Local> {
+    let now = Utc::now().naive_utc();
+    naive_to_local(&now, false).unwrap()
+}
+
+pub(super) fn naive_to_local(d: &NaiveDateTime, local: bool) -> LocalResult<DateTime<Local>> {
+    TZ_INFO.with(|maybe_cache| {
+        maybe_cache.borrow_mut().get_or_insert_with(Cache::default).offset(*d, local)
+    })
+}
+
+// we have to store the `Cache` in an option as it can't
+// be initalized in a static context.
+thread_local! {
+    static TZ_INFO: RefCell<Option<Cache>> = Default::default();
+}
+
+enum Source {
+    LocalTime { mtime: SystemTime },
+    Environment { hash: u64 },
+}
+
+impl Source {
+    fn new(env_tz: Option<&str>) -> Source {
+        match env_tz {
+            Some(tz) => {
+                let mut hasher = hash_map::DefaultHasher::new();
+                hasher.write(tz.as_bytes());
+                let hash = hasher.finish();
+                Source::Environment { hash }
+            }
+            None => match fs::symlink_metadata("/etc/localtime") {
+                Ok(data) => Source::LocalTime {
+                    // we have to pick a sensible default when the mtime fails
+                    // by picking SystemTime::now() we raise the probability of
+                    // the cache being invalidated if/when the mtime starts working
+                    mtime: data.modified().unwrap_or_else(|_| SystemTime::now()),
+                },
+                Err(_) => {
+                    // as above, now() should be a better default than some constant
+                    // TODO: see if we can improve caching in the case where the fallback is a valid timezone
+                    Source::LocalTime { mtime: SystemTime::now() }
+                }
+            },
+        }
+    }
+}
+
+struct Cache {
+    zone: TimeZone,
+    source: Source,
+    last_checked: SystemTime,
+}
+
+#[cfg(target_os = "android")]
+const TZDB_LOCATION: &str = " /system/usr/share/zoneinfo";
+
+#[cfg(target_os = "aix")]
+const TZDB_LOCATION: &str = "/usr/share/lib/zoneinfo";
+
+#[allow(dead_code)] // keeps the cfg simpler
+#[cfg(not(any(target_os = "android", target_os = "aix")))]
+const TZDB_LOCATION: &str = "/usr/share/zoneinfo";
+
+fn fallback_timezone() -> Option<TimeZone> {
+    let tz_name = iana_time_zone::get_timezone().ok()?;
+    let bytes = fs::read(format!("{}/{}", TZDB_LOCATION, tz_name)).ok()?;
+    TimeZone::from_tz_data(&bytes).ok()
+}
+
+impl Default for Cache {
+    fn default() -> Cache {
+        // default to UTC if no local timezone can be found
+        let env_tz = env::var("TZ").ok();
+        let env_ref = env_tz.as_ref().map(|s| s.as_str());
+        Cache {
+            last_checked: SystemTime::now(),
+            source: Source::new(env_ref),
+            zone: current_zone(env_ref),
+        }
+    }
+}
+
+fn current_zone(var: Option<&str>) -> TimeZone {
+    TimeZone::local(var).ok().or_else(fallback_timezone).unwrap_or_else(TimeZone::utc)
+}
+
+impl Cache {
+    fn offset(&mut self, d: NaiveDateTime, local: bool) -> LocalResult<DateTime<Local>> {
+        let now = SystemTime::now();
+
+        match now.duration_since(self.last_checked) {
+            // If the cache has been around for less than a second then we reuse it
+            // unconditionally. This is a reasonable tradeoff because the timezone
+            // generally won't be changing _that_ often, but if the time zone does
+            // change, it will reflect sufficiently quickly from an application
+            // user's perspective.
+            Ok(d) if d.as_secs() < 1 => (),
+            Ok(_) | Err(_) => {
+                let env_tz = env::var("TZ").ok();
+                let env_ref = env_tz.as_ref().map(|s| s.as_str());
+                let new_source = Source::new(env_ref);
+
+                let out_of_date = match (&self.source, &new_source) {
+                    // change from env to file or file to env, must recreate the zone
+                    (Source::Environment { .. }, Source::LocalTime { .. })
+                    | (Source::LocalTime { .. }, Source::Environment { .. }) => true,
+                    // stay as file, but mtime has changed
+                    (Source::LocalTime { mtime: old_mtime }, Source::LocalTime { mtime })
+                        if old_mtime != mtime =>
+                    {
+                        true
+                    }
+                    // stay as env, but hash of variable has changed
+                    (Source::Environment { hash: old_hash }, Source::Environment { hash })
+                        if old_hash != hash =>
+                    {
+                        true
+                    }
+                    // cache can be reused
+                    _ => false,
+                };
+
+                if out_of_date {
+                    self.zone = current_zone(env_ref);
+                }
+
+                self.last_checked = now;
+                self.source = new_source;
+            }
+        }
+
+        if !local {
+            let offset = self
+                .zone
+                .find_local_time_type(d.timestamp())
+                .expect("unable to select local time type")
+                .offset();
+
+            return match FixedOffset::east_opt(offset) {
+                Some(offset) => LocalResult::Single(DateTime::from_utc(d, offset)),
+                None => LocalResult::None,
+            };
+        }
+
+        // we pass through the year as the year of a local point in time must either be valid in that locale, or
+        // the entire time was skipped in which case we will return LocalResult::None anywa.
+        match self
+            .zone
+            .find_local_time_type_from_local(d.timestamp(), d.year())
+            .expect("unable to select local time type")
+        {
+            LocalResult::None => LocalResult::None,
+            LocalResult::Ambiguous(early, late) => {
+                let early_offset = FixedOffset::east_opt(early.offset()).unwrap();
+                let late_offset = FixedOffset::east_opt(late.offset()).unwrap();
+
+                LocalResult::Ambiguous(
+                    DateTime::from_utc(d - early_offset, early_offset),
+                    DateTime::from_utc(d - late_offset, late_offset),
+                )
+            }
+            LocalResult::Single(tt) => {
+                let offset = FixedOffset::east_opt(tt.offset()).unwrap();
+                LocalResult::Single(DateTime::from_utc(d - offset, offset))
+            }
+        }
+    }
+}

javascript-engine/external/chrono/src/offset/local/windows.rs

@@ -0,0 +1,278 @@
+// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::io;
+use std::mem;
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use winapi::shared::minwindef::*;
+use winapi::um::minwinbase::SYSTEMTIME;
+use winapi::um::timezoneapi::*;
+
+use super::{FixedOffset, Local};
+use crate::{DateTime, Datelike, LocalResult, NaiveDate, NaiveDateTime, NaiveTime, Timelike};
+
+pub(super) fn now() -> DateTime<Local> {
+    tm_to_datetime(Timespec::now().local())
+}
+
+/// Converts a local `NaiveDateTime` to the `time::Timespec`.
+pub(super) fn naive_to_local(d: &NaiveDateTime, local: bool) -> LocalResult<DateTime<Local>> {
+    let tm = Tm {
+        tm_sec: d.second() as i32,
+        tm_min: d.minute() as i32,
+        tm_hour: d.hour() as i32,
+        tm_mday: d.day() as i32,
+        tm_mon: d.month0() as i32, // yes, C is that strange...
+        tm_year: d.year() - 1900,  // this doesn't underflow, we know that d is `NaiveDateTime`.
+        tm_wday: 0,                // to_local ignores this
+        tm_yday: 0,                // and this
+        tm_isdst: -1,
+        // This seems pretty fake?
+        tm_utcoff: if local { 1 } else { 0 },
+        // do not set this, OS APIs are heavily inconsistent in terms of leap second handling
+        tm_nsec: 0,
+    };
+
+    let spec = Timespec {
+        sec: match local {
+            false => utc_tm_to_time(&tm),
+            true => local_tm_to_time(&tm),
+        },
+        nsec: tm.tm_nsec,
+    };
+
+    // Adjust for leap seconds
+    let mut tm = spec.local();
+    assert_eq!(tm.tm_nsec, 0);
+    tm.tm_nsec = d.nanosecond() as i32;
+
+    // #TODO - there should be ambiguous cases, investigate?
+    LocalResult::Single(tm_to_datetime(tm))
+}
+
+/// Converts a `time::Tm` struct into the timezone-aware `DateTime`.
+fn tm_to_datetime(mut tm: Tm) -> DateTime<Local> {
+    if tm.tm_sec >= 60 {
+        tm.tm_nsec += (tm.tm_sec - 59) * 1_000_000_000;
+        tm.tm_sec = 59;
+    }
+
+    let date = NaiveDate::from_ymd_opt(tm.tm_year + 1900, tm.tm_mon as u32 + 1, tm.tm_mday as u32)
+        .unwrap();
+    let time = NaiveTime::from_hms_nano(
+        tm.tm_hour as u32,
+        tm.tm_min as u32,
+        tm.tm_sec as u32,
+        tm.tm_nsec as u32,
+    );
+
+    let offset = FixedOffset::east_opt(tm.tm_utcoff).unwrap();
+    DateTime::from_utc(date.and_time(time) - offset, offset)
+}
+
+/// A record specifying a time value in seconds and nanoseconds, where
+/// nanoseconds represent the offset from the given second.
+///
+/// For example a timespec of 1.2 seconds after the beginning of the epoch would
+/// be represented as {sec: 1, nsec: 200000000}.
+struct Timespec {
+    sec: i64,
+    nsec: i32,
+}
+
+impl Timespec {
+    /// Constructs a timespec representing the current time in UTC.
+    fn now() -> Timespec {
+        let st =
+            SystemTime::now().duration_since(UNIX_EPOCH).expect("system time before Unix epoch");
+        Timespec { sec: st.as_secs() as i64, nsec: st.subsec_nanos() as i32 }
+    }
+
+    /// Converts this timespec into the system's local time.
+    fn local(self) -> Tm {
+        let mut tm = Tm {
+            tm_sec: 0,
+            tm_min: 0,
+            tm_hour: 0,
+            tm_mday: 0,
+            tm_mon: 0,
+            tm_year: 0,
+            tm_wday: 0,
+            tm_yday: 0,
+            tm_isdst: 0,
+            tm_utcoff: 0,
+            tm_nsec: 0,
+        };
+        time_to_local_tm(self.sec, &mut tm);
+        tm.tm_nsec = self.nsec;
+        tm
+    }
+}
+
+/// Holds a calendar date and time broken down into its components (year, month,
+/// day, and so on), also called a broken-down time value.
+// FIXME: use c_int instead of i32?
+#[repr(C)]
+struct Tm {
+    /// Seconds after the minute - [0, 60]
+    tm_sec: i32,
+
+    /// Minutes after the hour - [0, 59]
+    tm_min: i32,
+
+    /// Hours after midnight - [0, 23]
+    tm_hour: i32,
+
+    /// Day of the month - [1, 31]
+    tm_mday: i32,
+
+    /// Months since January - [0, 11]
+    tm_mon: i32,
+
+    /// Years since 1900
+    tm_year: i32,
+
+    /// Days since Sunday - [0, 6]. 0 = Sunday, 1 = Monday, ..., 6 = Saturday.
+    tm_wday: i32,
+
+    /// Days since January 1 - [0, 365]
+    tm_yday: i32,
+
+    /// Daylight Saving Time flag.
+    ///
+    /// This value is positive if Daylight Saving Time is in effect, zero if
+    /// Daylight Saving Time is not in effect, and negative if this information
+    /// is not available.
+    tm_isdst: i32,
+
+    /// Identifies the time zone that was used to compute this broken-down time
+    /// value, including any adjustment for Daylight Saving Time. This is the
+    /// number of seconds east of UTC. For example, for U.S. Pacific Daylight
+    /// Time, the value is `-7*60*60 = -25200`.
+    tm_utcoff: i32,
+
+    /// Nanoseconds after the second - [0, 10<sup>9</sup> - 1]
+    tm_nsec: i32,
+}
+
+const HECTONANOSECS_IN_SEC: i64 = 10_000_000;
+const HECTONANOSEC_TO_UNIX_EPOCH: i64 = 11_644_473_600 * HECTONANOSECS_IN_SEC;
+
+fn time_to_file_time(sec: i64) -> FILETIME {
+    let t = ((sec * HECTONANOSECS_IN_SEC) + HECTONANOSEC_TO_UNIX_EPOCH) as u64;
+    FILETIME { dwLowDateTime: t as DWORD, dwHighDateTime: (t >> 32) as DWORD }
+}
+
+fn file_time_as_u64(ft: &FILETIME) -> u64 {
+    ((ft.dwHighDateTime as u64) << 32) | (ft.dwLowDateTime as u64)
+}
+
+fn file_time_to_unix_seconds(ft: &FILETIME) -> i64 {
+    let t = file_time_as_u64(ft) as i64;
+    ((t - HECTONANOSEC_TO_UNIX_EPOCH) / HECTONANOSECS_IN_SEC) as i64
+}
+
+fn system_time_to_file_time(sys: &SYSTEMTIME) -> FILETIME {
+    unsafe {
+        let mut ft = mem::zeroed();
+        SystemTimeToFileTime(sys, &mut ft);
+        ft
+    }
+}
+
+fn tm_to_system_time(tm: &Tm) -> SYSTEMTIME {
+    let mut sys: SYSTEMTIME = unsafe { mem::zeroed() };
+    sys.wSecond = tm.tm_sec as WORD;
+    sys.wMinute = tm.tm_min as WORD;
+    sys.wHour = tm.tm_hour as WORD;
+    sys.wDay = tm.tm_mday as WORD;
+    sys.wDayOfWeek = tm.tm_wday as WORD;
+    sys.wMonth = (tm.tm_mon + 1) as WORD;
+    sys.wYear = (tm.tm_year + 1900) as WORD;
+    sys
+}
+
+fn system_time_to_tm(sys: &SYSTEMTIME, tm: &mut Tm) {
+    tm.tm_sec = sys.wSecond as i32;
+    tm.tm_min = sys.wMinute as i32;
+    tm.tm_hour = sys.wHour as i32;
+    tm.tm_mday = sys.wDay as i32;
+    tm.tm_wday = sys.wDayOfWeek as i32;
+    tm.tm_mon = (sys.wMonth - 1) as i32;
+    tm.tm_year = (sys.wYear - 1900) as i32;
+    tm.tm_yday = yday(tm.tm_year, tm.tm_mon + 1, tm.tm_mday);
+
+    fn yday(year: i32, month: i32, day: i32) -> i32 {
+        let leap = if month > 2 {
+            if year % 4 == 0 {
+                1
+            } else {
+                2
+            }
+        } else {
+            0
+        };
+        let july = if month > 7 { 1 } else { 0 };
+
+        (month - 1) * 30 + month / 2 + (day - 1) - leap + july
+    }
+}
+
+macro_rules! call {
+    ($name:ident($($arg:expr),*)) => {
+        if $name($($arg),*) == 0 {
+            panic!(concat!(stringify!($name), " failed with: {}"),
+                    io::Error::last_os_error());
+        }
+    }
+}
+
+fn time_to_local_tm(sec: i64, tm: &mut Tm) {
+    let ft = time_to_file_time(sec);
+    unsafe {
+        let mut utc = mem::zeroed();
+        let mut local = mem::zeroed();
+        call!(FileTimeToSystemTime(&ft, &mut utc));
+        call!(SystemTimeToTzSpecificLocalTime(0 as *const _, &mut utc, &mut local));
+        system_time_to_tm(&local, tm);
+
+        let local = system_time_to_file_time(&local);
+        let local_sec = file_time_to_unix_seconds(&local);
+
+        let mut tz = mem::zeroed();
+        GetTimeZoneInformation(&mut tz);
+
+        // SystemTimeToTzSpecificLocalTime already applied the biases so
+        // check if it non standard
+        tm.tm_utcoff = (local_sec - sec) as i32;
+        tm.tm_isdst = if tm.tm_utcoff == -60 * (tz.Bias + tz.StandardBias) { 0 } else { 1 };
+    }
+}
+
+fn utc_tm_to_time(tm: &Tm) -> i64 {
+    unsafe {
+        let mut ft = mem::zeroed();
+        let sys_time = tm_to_system_time(tm);
+        call!(SystemTimeToFileTime(&sys_time, &mut ft));
+        file_time_to_unix_seconds(&ft)
+    }
+}
+
+fn local_tm_to_time(tm: &Tm) -> i64 {
+    unsafe {
+        let mut ft = mem::zeroed();
+        let mut utc = mem::zeroed();
+        let mut sys_time = tm_to_system_time(tm);
+        call!(TzSpecificLocalTimeToSystemTime(0 as *mut _, &mut sys_time, &mut utc));
+        call!(SystemTimeToFileTime(&utc, &mut ft));
+        file_time_to_unix_seconds(&ft)
+    }
+}

javascript-engine/external/chrono/src/offset/mod.rs

@@ -0,0 +1,549 @@
+// This is a part of Chrono.
+// See README.md and LICENSE.txt for details.
+
+//! The time zone, which calculates offsets from the local time to UTC.
+//!
+//! There are four operations provided by the `TimeZone` trait:
+//!
+//! 1. Converting the local `NaiveDateTime` to `DateTime<Tz>`
+//! 2. Converting the UTC `NaiveDateTime` to `DateTime<Tz>`
+//! 3. Converting `DateTime<Tz>` to the local `NaiveDateTime`
+//! 4. Constructing `DateTime<Tz>` objects from various offsets
+//!
+//! 1 is used for constructors. 2 is used for the `with_timezone` method of date and time types.
+//! 3 is used for other methods, e.g. `year()` or `format()`, and provided by an associated type
+//! which implements `Offset` (which then passed to `TimeZone` for actual implementations).
+//! Technically speaking `TimeZone` has a total knowledge about given timescale,
+//! but `Offset` is used as a cache to avoid the repeated conversion
+//! and provides implementations for 1 and 3.
+//! An `TimeZone` instance can be reconstructed from the corresponding `Offset` instance.
+
+use core::fmt;
+
+use crate::format::{parse, ParseResult, Parsed, StrftimeItems};
+use crate::naive::{NaiveDate, NaiveDateTime, NaiveTime};
+use crate::Weekday;
+#[allow(deprecated)]
+use crate::{Date, DateTime};
+
+mod fixed;
+pub use self::fixed::FixedOffset;
+
+#[cfg(feature = "clock")]
+mod local;
+#[cfg(feature = "clock")]
+pub use self::local::Local;
+
+mod utc;
+pub use self::utc::Utc;
+
+/// The conversion result from the local time to the timezone-aware datetime types.
+#[derive(Clone, PartialEq, Debug, Copy, Eq, Hash)]
+pub enum LocalResult<T> {
+    /// Given local time representation is invalid.
+    /// This can occur when, for example, the positive timezone transition.
+    None,
+    /// Given local time representation has a single unique result.
+    Single(T),
+    /// Given local time representation has multiple results and thus ambiguous.
+    /// This can occur when, for example, the negative timezone transition.
+    Ambiguous(T /*min*/, T /*max*/),
+}
+
+impl<T> LocalResult<T> {
+    /// Returns `Some` only when the conversion result is unique, or `None` otherwise.
+    pub fn single(self) -> Option<T> {
+        match self {
+            LocalResult::Single(t) => Some(t),
+            _ => None,
+        }
+    }
+
+    /// Returns `Some` for the earliest possible conversion result, or `None` if none.
+    pub fn earliest(self) -> Option<T> {
+        match self {
+            LocalResult::Single(t) | LocalResult::Ambiguous(t, _) => Some(t),
+            _ => None,
+        }
+    }
+
+    /// Returns `Some` for the latest possible conversion result, or `None` if none.
+    pub fn latest(self) -> Option<T> {
+        match self {
+            LocalResult::Single(t) | LocalResult::Ambiguous(_, t) => Some(t),
+            _ => None,
+        }
+    }
+
+    /// Maps a `LocalResult<T>` into `LocalResult<U>` with given function.
+    pub fn map<U, F: FnMut(T) -> U>(self, mut f: F) -> LocalResult<U> {
+        match self {
+            LocalResult::None => LocalResult::None,
+            LocalResult::Single(v) => LocalResult::Single(f(v)),
+            LocalResult::Ambiguous(min, max) => LocalResult::Ambiguous(f(min), f(max)),
+        }
+    }
+}
+
+#[allow(deprecated)]
+impl<Tz: TimeZone> LocalResult<Date<Tz>> {
+    /// Makes a new `DateTime` from the current date and given `NaiveTime`.
+    /// The offset in the current date is preserved.
+    ///
+    /// Propagates any error. Ambiguous result would be discarded.
+    #[inline]
+    pub fn and_time(self, time: NaiveTime) -> LocalResult<DateTime<Tz>> {
+        match self {
+            LocalResult::Single(d) => {
+                d.and_time(time).map_or(LocalResult::None, LocalResult::Single)
+            }
+            _ => LocalResult::None,
+        }
+    }
+
+    /// Makes a new `DateTime` from the current date, hour, minute and second.
+    /// The offset in the current date is preserved.
+    ///
+    /// Propagates any error. Ambiguous result would be discarded.
+    #[inline]
+    pub fn and_hms_opt(self, hour: u32, min: u32, sec: u32) -> LocalResult<DateTime<Tz>> {
+        match self {
+            LocalResult::Single(d) => {
+                d.and_hms_opt(hour, min, sec).map_or(LocalResult::None, LocalResult::Single)
+            }
+            _ => LocalResult::None,
+        }
+    }
+
+    /// Makes a new `DateTime` from the current date, hour, minute, second and millisecond.
+    /// The millisecond part can exceed 1,000 in order to represent the leap second.
+    /// The offset in the current date is preserved.
+    ///
+    /// Propagates any error. Ambiguous result would be discarded.
+    #[inline]
+    pub fn and_hms_milli_opt(
+        self,
+        hour: u32,
+        min: u32,
+        sec: u32,
+        milli: u32,
+    ) -> LocalResult<DateTime<Tz>> {
+        match self {
+            LocalResult::Single(d) => d
+                .and_hms_milli_opt(hour, min, sec, milli)
+                .map_or(LocalResult::None, LocalResult::Single),
+            _ => LocalResult::None,
+        }
+    }
+
+    /// Makes a new `DateTime` from the current date, hour, minute, second and microsecond.
+    /// The microsecond part can exceed 1,000,000 in order to represent the leap second.
+    /// The offset in the current date is preserved.
+    ///
+    /// Propagates any error. Ambiguous result would be discarded.
+    #[inline]
+    pub fn and_hms_micro_opt(
+        self,
+        hour: u32,
+        min: u32,
+        sec: u32,
+        micro: u32,
+    ) -> LocalResult<DateTime<Tz>> {
+        match self {
+            LocalResult::Single(d) => d
+                .and_hms_micro_opt(hour, min, sec, micro)
+                .map_or(LocalResult::None, LocalResult::Single),
+            _ => LocalResult::None,
+        }
+    }
+
+    /// Makes a new `DateTime` from the current date, hour, minute, second and nanosecond.
+    /// The nanosecond part can exceed 1,000,000,000 in order to represent the leap second.
+    /// The offset in the current date is preserved.
+    ///
+    /// Propagates any error. Ambiguous result would be discarded.
+    #[inline]
+    pub fn and_hms_nano_opt(
+        self,
+        hour: u32,
+        min: u32,
+        sec: u32,
+        nano: u32,
+    ) -> LocalResult<DateTime<Tz>> {
+        match self {
+            LocalResult::Single(d) => d
+                .and_hms_nano_opt(hour, min, sec, nano)
+                .map_or(LocalResult::None, LocalResult::Single),
+            _ => LocalResult::None,
+        }
+    }
+}
+
+impl<T: fmt::Debug> LocalResult<T> {
+    /// Returns the single unique conversion result, or panics accordingly.
+    pub fn unwrap(self) -> T {
+        match self {
+            LocalResult::None => panic!("No such local time"),
+            LocalResult::Single(t) => t,
+            LocalResult::Ambiguous(t1, t2) => {
+                panic!("Ambiguous local time, ranging from {:?} to {:?}", t1, t2)
+            }
+        }
+    }
+}
+
+/// The offset from the local time to UTC.
+pub trait Offset: Sized + Clone + fmt::Debug {
+    /// Returns the fixed offset from UTC to the local time stored.
+    fn fix(&self) -> FixedOffset;
+}
+
+/// The time zone.
+///
+/// The methods here are the primarily constructors for [`Date`](../struct.Date.html) and
+/// [`DateTime`](../struct.DateTime.html) types.
+pub trait TimeZone: Sized + Clone {
+    /// An associated offset type.
+    /// This type is used to store the actual offset in date and time types.
+    /// The original `TimeZone` value can be recovered via `TimeZone::from_offset`.
+    type Offset: Offset;
+
+    /// Make a new `DateTime` from year, month, day, time components and current time zone.
+    ///
+    /// This assumes the proleptic Gregorian calendar, with the year 0 being 1 BCE.
+    ///
+    /// Returns `LocalResult::None` on invalid input data.
+    fn with_ymd_and_hms(
+        &self,
+        year: i32,
+        month: u32,
+        day: u32,
+        hour: u32,
+        min: u32,
+        sec: u32,
+    ) -> LocalResult<DateTime<Self>> {
+        match NaiveDate::from_ymd_opt(year, month, day).and_then(|d| d.and_hms_opt(hour, min, sec))
+        {
+            Some(dt) => self.from_local_datetime(&dt),
+            None => LocalResult::None,
+        }
+    }
+
+    /// Makes a new `Date` from year, month, day and the current time zone.
+    /// This assumes the proleptic Gregorian calendar, with the year 0 being 1 BCE.
+    ///
+    /// The time zone normally does not affect the date (unless it is between UTC-24 and UTC+24),
+    /// but it will propagate to the `DateTime` values constructed via this date.
+    ///
+    /// Panics on the out-of-range date, invalid month and/or day.
+    #[deprecated(since = "0.4.23", note = "use `with_ymd_and_hms()` instead")]
+    #[allow(deprecated)]
+    fn ymd(&self, year: i32, month: u32, day: u32) -> Date<Self> {
+        self.ymd_opt(year, month, day).unwrap()
+    }
+
+    /// Makes a new `Date` from year, month, day and the current time zone.
+    /// This assumes the proleptic Gregorian calendar, with the year 0 being 1 BCE.
+    ///
+    /// The time zone normally does not affect the date (unless it is between UTC-24 and UTC+24),
+    /// but it will propagate to the `DateTime` values constructed via this date.
+    ///
+    /// Returns `None` on the out-of-range date, invalid month and/or day.
+    #[deprecated(since = "0.4.23", note = "use `with_ymd_and_hms()` instead")]
+    #[allow(deprecated)]
+    fn ymd_opt(&self, year: i32, month: u32, day: u32) -> LocalResult<Date<Self>> {
+        match NaiveDate::from_ymd_opt(year, month, day) {
+            Some(d) => self.from_local_date(&d),
+            None => LocalResult::None,
+        }
+    }
+
+    /// Makes a new `Date` from year, day of year (DOY or "ordinal") and the current time zone.
+    /// This assumes the proleptic Gregorian calendar, with the year 0 being 1 BCE.
+    ///
+    /// The time zone normally does not affect the date (unless it is between UTC-24 and UTC+24),
+    /// but it will propagate to the `DateTime` values constructed via this date.
+    ///
+    /// Panics on the out-of-range date and/or invalid DOY.
+    #[deprecated(
+        since = "0.4.23",
+        note = "use `from_local_datetime()` with a `NaiveDateTime` instead"
+    )]
+    #[allow(deprecated)]
+    fn yo(&self, year: i32, ordinal: u32) -> Date<Self> {
+        self.yo_opt(year, ordinal).unwrap()
+    }
+
+    /// Makes a new `Date` from year, day of year (DOY or "ordinal") and the current time zone.
+    /// This assumes the proleptic Gregorian calendar, with the year 0 being 1 BCE.
+    ///
+    /// The time zone normally does not affect the date (unless it is between UTC-24 and UTC+24),
+    /// but it will propagate to the `DateTime` values constructed via this date.
+    ///
+    /// Returns `None` on the out-of-range date and/or invalid DOY.
+    #[deprecated(
+        since = "0.4.23",
+        note = "use `from_local_datetime()` with a `NaiveDateTime` instead"
+    )]
+    #[allow(deprecated)]
+    fn yo_opt(&self, year: i32, ordinal: u32) -> LocalResult<Date<Self>> {
+        match NaiveDate::from_yo_opt(year, ordinal) {
+            Some(d) => self.from_local_date(&d),
+            None => LocalResult::None,
+        }
+    }
+
+    /// Makes a new `Date` from ISO week date (year and week number), day of the week (DOW) and
+    /// the current time zone.
+    /// This assumes the proleptic Gregorian calendar, with the year 0 being 1 BCE.
+    /// The resulting `Date` may have a different year from the input year.
+    ///
+    /// The time zone normally does not affect the date (unless it is between UTC-24 and UTC+24),
+    /// but it will propagate to the `DateTime` values constructed via this date.
+    ///
+    /// Panics on the out-of-range date and/or invalid week number.
+    #[deprecated(
+        since = "0.4.23",
+        note = "use `from_local_datetime()` with a `NaiveDateTime` instead"
+    )]
+    #[allow(deprecated)]
+    fn isoywd(&self, year: i32, week: u32, weekday: Weekday) -> Date<Self> {
+        self.isoywd_opt(year, week, weekday).unwrap()
+    }
+
+    /// Makes a new `Date` from ISO week date (year and week number), day of the week (DOW) and
+    /// the current time zone.
+    /// This assumes the proleptic Gregorian calendar, with the year 0 being 1 BCE.
+    /// The resulting `Date` may have a different year from the input year.
+    ///
+    /// The time zone normally does not affect the date (unless it is between UTC-24 and UTC+24),
+    /// but it will propagate to the `DateTime` values constructed via this date.
+    ///
+    /// Returns `None` on the out-of-range date and/or invalid week number.
+    #[deprecated(
+        since = "0.4.23",
+        note = "use `from_local_datetime()` with a `NaiveDateTime` instead"
+    )]
+    #[allow(deprecated)]
+    fn isoywd_opt(&self, year: i32, week: u32, weekday: Weekday) -> LocalResult<Date<Self>> {
+        match NaiveDate::from_isoywd_opt(year, week, weekday) {
+            Some(d) => self.from_local_date(&d),
+            None => LocalResult::None,
+        }
+    }
+
+    /// Makes a new `DateTime` from the number of non-leap seconds
+    /// since January 1, 1970 0:00:00 UTC (aka "UNIX timestamp")
+    /// and the number of nanoseconds since the last whole non-leap second.
+    ///
+    /// Panics on the out-of-range number of seconds and/or invalid nanosecond,
+    /// for a non-panicking version see [`timestamp_opt`](#method.timestamp_opt).
+    #[deprecated(since = "0.4.23", note = "use `timestamp_opt()` instead")]
+    fn timestamp(&self, secs: i64, nsecs: u32) -> DateTime<Self> {
+        self.timestamp_opt(secs, nsecs).unwrap()
+    }
+
+    /// Makes a new `DateTime` from the number of non-leap seconds
+    /// since January 1, 1970 0:00:00 UTC (aka "UNIX timestamp")
+    /// and the number of nanoseconds since the last whole non-leap second.
+    ///
+    /// Returns `LocalResult::None` on out-of-range number of seconds and/or
+    /// invalid nanosecond, otherwise always returns `LocalResult::Single`.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use chrono::{Utc, TimeZone};
+    ///
+    /// assert_eq!(Utc.timestamp_opt(1431648000, 0).unwrap().to_string(), "2015-05-15 00:00:00 UTC");
+    /// ```
+    fn timestamp_opt(&self, secs: i64, nsecs: u32) -> LocalResult<DateTime<Self>> {
+        match NaiveDateTime::from_timestamp_opt(secs, nsecs) {
+            Some(dt) => LocalResult::Single(self.from_utc_datetime(&dt)),
+            None => LocalResult::None,
+        }
+    }
+
+    /// Makes a new `DateTime` from the number of non-leap milliseconds
+    /// since January 1, 1970 0:00:00 UTC (aka "UNIX timestamp").
+    ///
+    /// Panics on out-of-range number of milliseconds for a non-panicking
+    /// version see [`timestamp_millis_opt`](#method.timestamp_millis_opt).
+    #[deprecated(since = "0.4.23", note = "use `timestamp_millis_opt()` instead")]
+    fn timestamp_millis(&self, millis: i64) -> DateTime<Self> {
+        self.timestamp_millis_opt(millis).unwrap()
+    }
+
+    /// Makes a new `DateTime` from the number of non-leap milliseconds
+    /// since January 1, 1970 0:00:00 UTC (aka "UNIX timestamp").
+    ///
+    ///
+    /// Returns `LocalResult::None` on out-of-range number of milliseconds
+    /// and/or invalid nanosecond, otherwise always returns
+    /// `LocalResult::Single`.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use chrono::{Utc, TimeZone, LocalResult};
+    /// match Utc.timestamp_millis_opt(1431648000) {
+    ///     LocalResult::Single(dt) => assert_eq!(dt.timestamp(), 1431648),
+    ///     _ => panic!("Incorrect timestamp_millis"),
+    /// };
+    /// ```
+    fn timestamp_millis_opt(&self, millis: i64) -> LocalResult<DateTime<Self>> {
+        let (mut secs, mut millis) = (millis / 1000, millis % 1000);
+        if millis < 0 {
+            secs -= 1;
+            millis += 1000;
+        }
+        self.timestamp_opt(secs, millis as u32 * 1_000_000)
+    }
+
+    /// Makes a new `DateTime` from the number of non-leap nanoseconds
+    /// since January 1, 1970 0:00:00 UTC (aka "UNIX timestamp").
+    ///
+    /// Unlike [`timestamp_millis`](#method.timestamp_millis), this never
+    /// panics.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use chrono::{Utc, TimeZone};
+    ///
+    /// assert_eq!(Utc.timestamp_nanos(1431648000000000).timestamp(), 1431648);
+    /// ```
+    fn timestamp_nanos(&self, nanos: i64) -> DateTime<Self> {
+        let (mut secs, mut nanos) = (nanos / 1_000_000_000, nanos % 1_000_000_000);
+        if nanos < 0 {
+            secs -= 1;
+            nanos += 1_000_000_000;
+        }
+        self.timestamp_opt(secs, nanos as u32).unwrap()
+    }
+
+    /// Parses a string with the specified format string and returns a
+    /// `DateTime` with the current offset.
+    ///
+    /// See the [`crate::format::strftime`] module on the
+    /// supported escape sequences.
+    ///
+    /// If the to-be-parsed string includes an offset, it *must* match the
+    /// offset of the TimeZone, otherwise an error will be returned.
+    ///
+    /// See also [`DateTime::parse_from_str`] which gives a [`DateTime`] with
+    /// parsed [`FixedOffset`].
+    fn datetime_from_str(&self, s: &str, fmt: &str) -> ParseResult<DateTime<Self>> {
+        let mut parsed = Parsed::new();
+        parse(&mut parsed, s, StrftimeItems::new(fmt))?;
+        parsed.to_datetime_with_timezone(self)
+    }
+
+    /// Reconstructs the time zone from the offset.
+    fn from_offset(offset: &Self::Offset) -> Self;
+
+    /// Creates the offset(s) for given local `NaiveDate` if possible.
+    fn offset_from_local_date(&self, local: &NaiveDate) -> LocalResult<Self::Offset>;
+
+    /// Creates the offset(s) for given local `NaiveDateTime` if possible.
+    fn offset_from_local_datetime(&self, local: &NaiveDateTime) -> LocalResult<Self::Offset>;
+
+    /// Converts the local `NaiveDate` to the timezone-aware `Date` if possible.
+    #[allow(clippy::wrong_self_convention)]
+    #[deprecated(since = "0.4.23", note = "use `from_local_datetime()` instead")]
+    #[allow(deprecated)]
+    fn from_local_date(&self, local: &NaiveDate) -> LocalResult<Date<Self>> {
+        self.offset_from_local_date(local).map(|offset| {
+            // since FixedOffset is within +/- 1 day, the date is never affected
+            Date::from_utc(*local, offset)
+        })
+    }
+
+    /// Converts the local `NaiveDateTime` to the timezone-aware `DateTime` if possible.
+    #[allow(clippy::wrong_self_convention)]
+    fn from_local_datetime(&self, local: &NaiveDateTime) -> LocalResult<DateTime<Self>> {
+        self.offset_from_local_datetime(local)
+            .map(|offset| DateTime::from_utc(*local - offset.fix(), offset))
+    }
+
+    /// Creates the offset for given UTC `NaiveDate`. This cannot fail.
+    fn offset_from_utc_date(&self, utc: &NaiveDate) -> Self::Offset;
+
+    /// Creates the offset for given UTC `NaiveDateTime`. This cannot fail.
+    fn offset_from_utc_datetime(&self, utc: &NaiveDateTime) -> Self::Offset;
+
+    /// Converts the UTC `NaiveDate` to the local time.
+    /// The UTC is continuous and thus this cannot fail (but can give the duplicate local time).
+    #[allow(clippy::wrong_self_convention)]
+    #[deprecated(since = "0.4.23", note = "use `from_utc_datetime()` instead")]
+    #[allow(deprecated)]
+    fn from_utc_date(&self, utc: &NaiveDate) -> Date<Self> {
+        Date::from_utc(*utc, self.offset_from_utc_date(utc))
+    }
+
+    /// Converts the UTC `NaiveDateTime` to the local time.
+    /// The UTC is continuous and thus this cannot fail (but can give the duplicate local time).
+    #[allow(clippy::wrong_self_convention)]
+    fn from_utc_datetime(&self, utc: &NaiveDateTime) -> DateTime<Self> {
+        DateTime::from_utc(*utc, self.offset_from_utc_datetime(utc))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_negative_millis() {
+        let dt = Utc.timestamp_millis_opt(-1000).unwrap();
+        assert_eq!(dt.to_string(), "1969-12-31 23:59:59 UTC");
+        let dt = Utc.timestamp_millis_opt(-7000).unwrap();
+        assert_eq!(dt.to_string(), "1969-12-31 23:59:53 UTC");
+        let dt = Utc.timestamp_millis_opt(-7001).unwrap();
+        assert_eq!(dt.to_string(), "1969-12-31 23:59:52.999 UTC");
+        let dt = Utc.timestamp_millis_opt(-7003).unwrap();
+        assert_eq!(dt.to_string(), "1969-12-31 23:59:52.997 UTC");
+        let dt = Utc.timestamp_millis_opt(-999).unwrap();
+        assert_eq!(dt.to_string(), "1969-12-31 23:59:59.001 UTC");
+        let dt = Utc.timestamp_millis_opt(-1).unwrap();
+        assert_eq!(dt.to_string(), "1969-12-31 23:59:59.999 UTC");
+        let dt = Utc.timestamp_millis_opt(-60000).unwrap();
+        assert_eq!(dt.to_string(), "1969-12-31 23:59:00 UTC");
+        let dt = Utc.timestamp_millis_opt(-3600000).unwrap();
+        assert_eq!(dt.to_string(), "1969-12-31 23:00:00 UTC");
+
+        for (millis, expected) in &[
+            (-7000, "1969-12-31 23:59:53 UTC"),
+            (-7001, "1969-12-31 23:59:52.999 UTC"),
+            (-7003, "1969-12-31 23:59:52.997 UTC"),
+        ] {
+            match Utc.timestamp_millis_opt(*millis) {
+                LocalResult::Single(dt) => {
+                    assert_eq!(dt.to_string(), *expected);
+                }
+                e => panic!("Got {:?} instead of an okay answer", e),
+            }
+        }
+    }
+
+    #[test]
+    fn test_negative_nanos() {
+        let dt = Utc.timestamp_nanos(-1_000_000_000);
+        assert_eq!(dt.to_string(), "1969-12-31 23:59:59 UTC");
+        let dt = Utc.timestamp_nanos(-999_999_999);
+        assert_eq!(dt.to_string(), "1969-12-31 23:59:59.000000001 UTC");
+        let dt = Utc.timestamp_nanos(-1);
+        assert_eq!(dt.to_string(), "1969-12-31 23:59:59.999999999 UTC");
+        let dt = Utc.timestamp_nanos(-60_000_000_000);
+        assert_eq!(dt.to_string(), "1969-12-31 23:59:00 UTC");
+        let dt = Utc.timestamp_nanos(-3_600_000_000_000);
+        assert_eq!(dt.to_string(), "1969-12-31 23:00:00 UTC");
+    }
+
+    #[test]
+    fn test_nanos_never_panics() {
+        Utc.timestamp_nanos(i64::max_value());
+        Utc.timestamp_nanos(i64::default());
+        Utc.timestamp_nanos(i64::min_value());
+    }
+}

javascript-engine/external/chrono/src/offset/utc.rs

@@ -0,0 +1,125 @@
+// This is a part of Chrono.
+// See README.md and LICENSE.txt for details.
+
+//! The UTC (Coordinated Universal Time) time zone.
+
+use core::fmt;
+#[cfg(all(
+    feature = "clock",
+    not(all(
+        target_arch = "wasm32",
+        feature = "wasmbind",
+        not(any(target_os = "emscripten", target_os = "wasi"))
+    ))
+))]
+use std::time::{SystemTime, UNIX_EPOCH};
+
+#[cfg(feature = "rkyv")]
+use rkyv::{Archive, Deserialize, Serialize};
+
+use super::{FixedOffset, LocalResult, Offset, TimeZone};
+use crate::naive::{NaiveDate, NaiveDateTime};
+#[cfg(feature = "clock")]
+#[allow(deprecated)]
+use crate::{Date, DateTime};
+
+/// The UTC time zone. This is the most efficient time zone when you don't need the local time.
+/// It is also used as an offset (which is also a dummy type).
+///
+/// Using the [`TimeZone`](./trait.TimeZone.html) methods
+/// on the UTC struct is the preferred way to construct `DateTime<Utc>`
+/// instances.
+///
+/// # Example
+///
+/// ```
+/// use chrono::{DateTime, TimeZone, NaiveDateTime, Utc};
+///
+/// let dt = DateTime::<Utc>::from_utc(NaiveDateTime::from_timestamp(61, 0), Utc);
+///
+/// assert_eq!(Utc.timestamp(61, 0), dt);
+/// assert_eq!(Utc.with_ymd_and_hms(1970, 1, 1, 0, 1, 1).unwrap(), dt);
+/// ```
+#[derive(Copy, Clone, PartialEq, Eq)]
+#[cfg_attr(feature = "rkyv", derive(Archive, Deserialize, Serialize))]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
+pub struct Utc;
+
+#[cfg(feature = "clock")]
+#[cfg_attr(docsrs, doc(cfg(feature = "clock")))]
+impl Utc {
+    /// Returns a `Date` which corresponds to the current date.
+    #[deprecated(
+        since = "0.4.23",
+        note = "use `Utc::now()` instead, potentially with `.date_naive()`"
+    )]
+    #[allow(deprecated)]
+    pub fn today() -> Date<Utc> {
+        Utc::now().date()
+    }
+
+    /// Returns a `DateTime` which corresponds to the current date and time.
+    #[cfg(not(all(
+        target_arch = "wasm32",
+        feature = "wasmbind",
+        not(any(target_os = "emscripten", target_os = "wasi"))
+    )))]
+    pub fn now() -> DateTime<Utc> {
+        let now =
+            SystemTime::now().duration_since(UNIX_EPOCH).expect("system time before Unix epoch");
+        let naive =
+            NaiveDateTime::from_timestamp_opt(now.as_secs() as i64, now.subsec_nanos()).unwrap();
+        DateTime::from_utc(naive, Utc)
+    }
+
+    /// Returns a `DateTime` which corresponds to the current date and time.
+    #[cfg(all(
+        target_arch = "wasm32",
+        feature = "wasmbind",
+        not(any(target_os = "emscripten", target_os = "wasi"))
+    ))]
+    pub fn now() -> DateTime<Utc> {
+        let now = js_sys::Date::new_0();
+        DateTime::<Utc>::from(now)
+    }
+}
+
+impl TimeZone for Utc {
+    type Offset = Utc;
+
+    fn from_offset(_state: &Utc) -> Utc {
+        Utc
+    }
+
+    fn offset_from_local_date(&self, _local: &NaiveDate) -> LocalResult<Utc> {
+        LocalResult::Single(Utc)
+    }
+    fn offset_from_local_datetime(&self, _local: &NaiveDateTime) -> LocalResult<Utc> {
+        LocalResult::Single(Utc)
+    }
+
+    fn offset_from_utc_date(&self, _utc: &NaiveDate) -> Utc {
+        Utc
+    }
+    fn offset_from_utc_datetime(&self, _utc: &NaiveDateTime) -> Utc {
+        Utc
+    }
+}
+
+impl Offset for Utc {
+    fn fix(&self) -> FixedOffset {
+        FixedOffset::east_opt(0).unwrap()
+    }
+}
+
+impl fmt::Debug for Utc {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "Z")
+    }
+}
+
+impl fmt::Display for Utc {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "UTC")
+    }
+}

javascript-engine/external/chrono/src/oldtime.rs

@@ -0,0 +1,765 @@
+// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Temporal quantification
+
+use core::ops::{Add, Div, Mul, Neg, Sub};
+use core::time::Duration as StdDuration;
+use core::{fmt, i64};
+#[cfg(any(feature = "std", test))]
+use std::error::Error;
+
+#[cfg(feature = "rkyv")]
+use rkyv::{Archive, Deserialize, Serialize};
+
+/// The number of nanoseconds in a microsecond.
+const NANOS_PER_MICRO: i32 = 1000;
+/// The number of nanoseconds in a millisecond.
+const NANOS_PER_MILLI: i32 = 1000_000;
+/// The number of nanoseconds in seconds.
+const NANOS_PER_SEC: i32 = 1_000_000_000;
+/// The number of microseconds per second.
+const MICROS_PER_SEC: i64 = 1000_000;
+/// The number of milliseconds per second.
+const MILLIS_PER_SEC: i64 = 1000;
+/// The number of seconds in a minute.
+const SECS_PER_MINUTE: i64 = 60;
+/// The number of seconds in an hour.
+const SECS_PER_HOUR: i64 = 3600;
+/// The number of (non-leap) seconds in days.
+const SECS_PER_DAY: i64 = 86400;
+/// The number of (non-leap) seconds in a week.
+const SECS_PER_WEEK: i64 = 604800;
+
+macro_rules! try_opt {
+    ($e:expr) => {
+        match $e {
+            Some(v) => v,
+            None => return None,
+        }
+    };
+}
+
+/// ISO 8601 time duration with nanosecond precision.
+///
+/// This also allows for the negative duration; see individual methods for details.
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Debug)]
+#[cfg_attr(feature = "rkyv", derive(Archive, Deserialize, Serialize))]
+pub struct Duration {
+    secs: i64,
+    nanos: i32, // Always 0 <= nanos < NANOS_PER_SEC
+}
+
+/// The minimum possible `Duration`: `i64::MIN` milliseconds.
+pub(crate) const MIN: Duration = Duration {
+    secs: i64::MIN / MILLIS_PER_SEC - 1,
+    nanos: NANOS_PER_SEC + (i64::MIN % MILLIS_PER_SEC) as i32 * NANOS_PER_MILLI,
+};
+
+/// The maximum possible `Duration`: `i64::MAX` milliseconds.
+pub(crate) const MAX: Duration = Duration {
+    secs: i64::MAX / MILLIS_PER_SEC,
+    nanos: (i64::MAX % MILLIS_PER_SEC) as i32 * NANOS_PER_MILLI,
+};
+
+impl Duration {
+    /// Makes a new `Duration` with given number of weeks.
+    /// Equivalent to `Duration::seconds(weeks * 7 * 24 * 60 * 60)` with overflow checks.
+    /// Panics when the duration is out of bounds.
+    #[inline]
+    pub fn weeks(weeks: i64) -> Duration {
+        let secs = weeks.checked_mul(SECS_PER_WEEK).expect("Duration::weeks out of bounds");
+        Duration::seconds(secs)
+    }
+
+    /// Makes a new `Duration` with given number of days.
+    /// Equivalent to `Duration::seconds(days * 24 * 60 * 60)` with overflow checks.
+    /// Panics when the duration is out of bounds.
+    #[inline]
+    pub fn days(days: i64) -> Duration {
+        let secs = days.checked_mul(SECS_PER_DAY).expect("Duration::days out of bounds");
+        Duration::seconds(secs)
+    }
+
+    /// Makes a new `Duration` with given number of hours.
+    /// Equivalent to `Duration::seconds(hours * 60 * 60)` with overflow checks.
+    /// Panics when the duration is out of bounds.
+    #[inline]
+    pub fn hours(hours: i64) -> Duration {
+        let secs = hours.checked_mul(SECS_PER_HOUR).expect("Duration::hours ouf of bounds");
+        Duration::seconds(secs)
+    }
+
+    /// Makes a new `Duration` with given number of minutes.
+    /// Equivalent to `Duration::seconds(minutes * 60)` with overflow checks.
+    /// Panics when the duration is out of bounds.
+    #[inline]
+    pub fn minutes(minutes: i64) -> Duration {
+        let secs = minutes.checked_mul(SECS_PER_MINUTE).expect("Duration::minutes out of bounds");
+        Duration::seconds(secs)
+    }
+
+    /// Makes a new `Duration` with given number of seconds.
+    /// Panics when the duration is more than `i64::MAX` seconds
+    /// or less than `i64::MIN` seconds.
+    #[inline]
+    pub fn seconds(seconds: i64) -> Duration {
+        let d = Duration { secs: seconds, nanos: 0 };
+        if d < MIN || d > MAX {
+            panic!("Duration::seconds out of bounds");
+        }
+        d
+    }
+
+    /// Makes a new `Duration` with given number of milliseconds.
+    #[inline]
+    pub fn milliseconds(milliseconds: i64) -> Duration {
+        let (secs, millis) = div_mod_floor_64(milliseconds, MILLIS_PER_SEC);
+        let nanos = millis as i32 * NANOS_PER_MILLI;
+        Duration { secs: secs, nanos: nanos }
+    }
+
+    /// Makes a new `Duration` with given number of microseconds.
+    #[inline]
+    pub fn microseconds(microseconds: i64) -> Duration {
+        let (secs, micros) = div_mod_floor_64(microseconds, MICROS_PER_SEC);
+        let nanos = micros as i32 * NANOS_PER_MICRO;
+        Duration { secs: secs, nanos: nanos }
+    }
+
+    /// Makes a new `Duration` with given number of nanoseconds.
+    #[inline]
+    pub fn nanoseconds(nanos: i64) -> Duration {
+        let (secs, nanos) = div_mod_floor_64(nanos, NANOS_PER_SEC as i64);
+        Duration { secs: secs, nanos: nanos as i32 }
+    }
+
+    /// Returns the total number of whole weeks in the duration.
+    #[inline]
+    pub fn num_weeks(&self) -> i64 {
+        self.num_days() / 7
+    }
+
+    /// Returns the total number of whole days in the duration.
+    pub fn num_days(&self) -> i64 {
+        self.num_seconds() / SECS_PER_DAY
+    }
+
+    /// Returns the total number of whole hours in the duration.
+    #[inline]
+    pub fn num_hours(&self) -> i64 {
+        self.num_seconds() / SECS_PER_HOUR
+    }
+
+    /// Returns the total number of whole minutes in the duration.
+    #[inline]
+    pub fn num_minutes(&self) -> i64 {
+        self.num_seconds() / SECS_PER_MINUTE
+    }
+
+    /// Returns the total number of whole seconds in the duration.
+    pub fn num_seconds(&self) -> i64 {
+        // If secs is negative, nanos should be subtracted from the duration.
+        if self.secs < 0 && self.nanos > 0 {
+            self.secs + 1
+        } else {
+            self.secs
+        }
+    }
+
+    /// Returns the number of nanoseconds such that
+    /// `nanos_mod_sec() + num_seconds() * NANOS_PER_SEC` is the total number of
+    /// nanoseconds in the duration.
+    fn nanos_mod_sec(&self) -> i32 {
+        if self.secs < 0 && self.nanos > 0 {
+            self.nanos - NANOS_PER_SEC
+        } else {
+            self.nanos
+        }
+    }
+
+    /// Returns the total number of whole milliseconds in the duration,
+    pub fn num_milliseconds(&self) -> i64 {
+        // A proper Duration will not overflow, because MIN and MAX are defined
+        // such that the range is exactly i64 milliseconds.
+        let secs_part = self.num_seconds() * MILLIS_PER_SEC;
+        let nanos_part = self.nanos_mod_sec() / NANOS_PER_MILLI;
+        secs_part + nanos_part as i64
+    }
+
+    /// Returns the total number of whole microseconds in the duration,
+    /// or `None` on overflow (exceeding 2^63 microseconds in either direction).
+    pub fn num_microseconds(&self) -> Option<i64> {
+        let secs_part = try_opt!(self.num_seconds().checked_mul(MICROS_PER_SEC));
+        let nanos_part = self.nanos_mod_sec() / NANOS_PER_MICRO;
+        secs_part.checked_add(nanos_part as i64)
+    }
+
+    /// Returns the total number of whole nanoseconds in the duration,
+    /// or `None` on overflow (exceeding 2^63 nanoseconds in either direction).
+    pub fn num_nanoseconds(&self) -> Option<i64> {
+        let secs_part = try_opt!(self.num_seconds().checked_mul(NANOS_PER_SEC as i64));
+        let nanos_part = self.nanos_mod_sec();
+        secs_part.checked_add(nanos_part as i64)
+    }
+
+    /// Add two durations, returning `None` if overflow occurred.
+    pub fn checked_add(&self, rhs: &Duration) -> Option<Duration> {
+        let mut secs = try_opt!(self.secs.checked_add(rhs.secs));
+        let mut nanos = self.nanos + rhs.nanos;
+        if nanos >= NANOS_PER_SEC {
+            nanos -= NANOS_PER_SEC;
+            secs = try_opt!(secs.checked_add(1));
+        }
+        let d = Duration { secs: secs, nanos: nanos };
+        // Even if d is within the bounds of i64 seconds,
+        // it might still overflow i64 milliseconds.
+        if d < MIN || d > MAX {
+            None
+        } else {
+            Some(d)
+        }
+    }
+
+    /// Subtract two durations, returning `None` if overflow occurred.
+    pub fn checked_sub(&self, rhs: &Duration) -> Option<Duration> {
+        let mut secs = try_opt!(self.secs.checked_sub(rhs.secs));
+        let mut nanos = self.nanos - rhs.nanos;
+        if nanos < 0 {
+            nanos += NANOS_PER_SEC;
+            secs = try_opt!(secs.checked_sub(1));
+        }
+        let d = Duration { secs: secs, nanos: nanos };
+        // Even if d is within the bounds of i64 seconds,
+        // it might still overflow i64 milliseconds.
+        if d < MIN || d > MAX {
+            None
+        } else {
+            Some(d)
+        }
+    }
+
+    /// Returns the duration as an absolute (non-negative) value.
+    #[inline]
+    pub fn abs(&self) -> Duration {
+        if self.secs < 0 && self.nanos != 0 {
+            Duration { secs: (self.secs + 1).abs(), nanos: NANOS_PER_SEC - self.nanos }
+        } else {
+            Duration { secs: self.secs.abs(), nanos: self.nanos }
+        }
+    }
+
+    /// The minimum possible `Duration`: `i64::MIN` milliseconds.
+    #[inline]
+    pub fn min_value() -> Duration {
+        MIN
+    }
+
+    /// The maximum possible `Duration`: `i64::MAX` milliseconds.
+    #[inline]
+    pub fn max_value() -> Duration {
+        MAX
+    }
+
+    /// A duration where the stored seconds and nanoseconds are equal to zero.
+    #[inline]
+    pub fn zero() -> Duration {
+        Duration { secs: 0, nanos: 0 }
+    }
+
+    /// Returns `true` if the duration equals `Duration::zero()`.
+    #[inline]
+    pub fn is_zero(&self) -> bool {
+        self.secs == 0 && self.nanos == 0
+    }
+
+    /// Creates a `time::Duration` object from `std::time::Duration`
+    ///
+    /// This function errors when original duration is larger than the maximum
+    /// value supported for this type.
+    pub fn from_std(duration: StdDuration) -> Result<Duration, OutOfRangeError> {
+        // We need to check secs as u64 before coercing to i64
+        if duration.as_secs() > MAX.secs as u64 {
+            return Err(OutOfRangeError(()));
+        }
+        let d = Duration { secs: duration.as_secs() as i64, nanos: duration.subsec_nanos() as i32 };
+        if d > MAX {
+            return Err(OutOfRangeError(()));
+        }
+        Ok(d)
+    }
+
+    /// Creates a `std::time::Duration` object from `time::Duration`
+    ///
+    /// This function errors when duration is less than zero. As standard
+    /// library implementation is limited to non-negative values.
+    pub fn to_std(&self) -> Result<StdDuration, OutOfRangeError> {
+        if self.secs < 0 {
+            return Err(OutOfRangeError(()));
+        }
+        Ok(StdDuration::new(self.secs as u64, self.nanos as u32))
+    }
+}
+
+impl Neg for Duration {
+    type Output = Duration;
+
+    #[inline]
+    fn neg(self) -> Duration {
+        if self.nanos == 0 {
+            Duration { secs: -self.secs, nanos: 0 }
+        } else {
+            Duration { secs: -self.secs - 1, nanos: NANOS_PER_SEC - self.nanos }
+        }
+    }
+}
+
+impl Add for Duration {
+    type Output = Duration;
+
+    fn add(self, rhs: Duration) -> Duration {
+        let mut secs = self.secs + rhs.secs;
+        let mut nanos = self.nanos + rhs.nanos;
+        if nanos >= NANOS_PER_SEC {
+            nanos -= NANOS_PER_SEC;
+            secs += 1;
+        }
+        Duration { secs: secs, nanos: nanos }
+    }
+}
+
+impl Sub for Duration {
+    type Output = Duration;
+
+    fn sub(self, rhs: Duration) -> Duration {
+        let mut secs = self.secs - rhs.secs;
+        let mut nanos = self.nanos - rhs.nanos;
+        if nanos < 0 {
+            nanos += NANOS_PER_SEC;
+            secs -= 1;
+        }
+        Duration { secs: secs, nanos: nanos }
+    }
+}
+
+impl Mul<i32> for Duration {
+    type Output = Duration;
+
+    fn mul(self, rhs: i32) -> Duration {
+        // Multiply nanoseconds as i64, because it cannot overflow that way.
+        let total_nanos = self.nanos as i64 * rhs as i64;
+        let (extra_secs, nanos) = div_mod_floor_64(total_nanos, NANOS_PER_SEC as i64);
+        let secs = self.secs * rhs as i64 + extra_secs;
+        Duration { secs: secs, nanos: nanos as i32 }
+    }
+}
+
+impl Div<i32> for Duration {
+    type Output = Duration;
+
+    fn div(self, rhs: i32) -> Duration {
+        let mut secs = self.secs / rhs as i64;
+        let carry = self.secs - secs * rhs as i64;
+        let extra_nanos = carry * NANOS_PER_SEC as i64 / rhs as i64;
+        let mut nanos = self.nanos / rhs + extra_nanos as i32;
+        if nanos >= NANOS_PER_SEC {
+            nanos -= NANOS_PER_SEC;
+            secs += 1;
+        }
+        if nanos < 0 {
+            nanos += NANOS_PER_SEC;
+            secs -= 1;
+        }
+        Duration { secs: secs, nanos: nanos }
+    }
+}
+
+#[cfg(any(feature = "std", test))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+impl<'a> std::iter::Sum<&'a Duration> for Duration {
+    fn sum<I: Iterator<Item = &'a Duration>>(iter: I) -> Duration {
+        iter.fold(Duration::zero(), |acc, x| acc + *x)
+    }
+}
+
+#[cfg(any(feature = "std", test))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+impl std::iter::Sum<Duration> for Duration {
+    fn sum<I: Iterator<Item = Duration>>(iter: I) -> Duration {
+        iter.fold(Duration::zero(), |acc, x| acc + x)
+    }
+}
+
+impl fmt::Display for Duration {
+    /// Format a duration using the [ISO 8601] format
+    ///
+    /// [ISO 8601]: https://en.wikipedia.org/wiki/ISO_8601#Durations
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        // technically speaking, negative duration is not valid ISO 8601,
+        // but we need to print it anyway.
+        let (abs, sign) = if self.secs < 0 { (-*self, "-") } else { (*self, "") };
+
+        let days = abs.secs / SECS_PER_DAY;
+        let secs = abs.secs - days * SECS_PER_DAY;
+        let hasdate = days != 0;
+        let hastime = (secs != 0 || abs.nanos != 0) || !hasdate;
+
+        write!(f, "{}P", sign)?;
+
+        if hasdate {
+            write!(f, "{}D", days)?;
+        }
+        if hastime {
+            if abs.nanos == 0 {
+                write!(f, "T{}S", secs)?;
+            } else if abs.nanos % NANOS_PER_MILLI == 0 {
+                write!(f, "T{}.{:03}S", secs, abs.nanos / NANOS_PER_MILLI)?;
+            } else if abs.nanos % NANOS_PER_MICRO == 0 {
+                write!(f, "T{}.{:06}S", secs, abs.nanos / NANOS_PER_MICRO)?;
+            } else {
+                write!(f, "T{}.{:09}S", secs, abs.nanos)?;
+            }
+        }
+        Ok(())
+    }
+}
+
+/// Represents error when converting `Duration` to/from a standard library
+/// implementation
+///
+/// The `std::time::Duration` supports a range from zero to `u64::MAX`
+/// *seconds*, while this module supports signed range of up to
+/// `i64::MAX` of *milliseconds*.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct OutOfRangeError(());
+
+impl fmt::Display for OutOfRangeError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "Source duration value is out of range for the target type")
+    }
+}
+
+#[cfg(any(feature = "std", test))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+impl Error for OutOfRangeError {
+    #[allow(deprecated)]
+    fn description(&self) -> &str {
+        "out of range error"
+    }
+}
+
+// Copied from libnum
+#[inline]
+fn div_mod_floor_64(this: i64, other: i64) -> (i64, i64) {
+    (div_floor_64(this, other), mod_floor_64(this, other))
+}
+
+#[inline]
+fn div_floor_64(this: i64, other: i64) -> i64 {
+    match div_rem_64(this, other) {
+        (d, r) if (r > 0 && other < 0) || (r < 0 && other > 0) => d - 1,
+        (d, _) => d,
+    }
+}
+
+#[inline]
+fn mod_floor_64(this: i64, other: i64) -> i64 {
+    match this % other {
+        r if (r > 0 && other < 0) || (r < 0 && other > 0) => r + other,
+        r => r,
+    }
+}
+
+#[inline]
+fn div_rem_64(this: i64, other: i64) -> (i64, i64) {
+    (this / other, this % other)
+}
+
+#[cfg(feature = "arbitrary")]
+impl arbitrary::Arbitrary<'_> for Duration {
+    fn arbitrary(u: &mut arbitrary::Unstructured) -> arbitrary::Result<Duration> {
+        const MIN_SECS: i64 = i64::MIN / MILLIS_PER_SEC - 1;
+        const MAX_SECS: i64 = i64::MAX / MILLIS_PER_SEC;
+
+        let secs: i64 = u.int_in_range(MIN_SECS..=MAX_SECS)?;
+        let nanos: i32 = u.int_in_range(0..=(NANOS_PER_SEC - 1))?;
+        let duration = Duration { secs, nanos };
+
+        if duration < MIN || duration > MAX {
+            Err(arbitrary::Error::IncorrectFormat)
+        } else {
+            Ok(duration)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{Duration, OutOfRangeError, MAX, MIN};
+    use std::time::Duration as StdDuration;
+    use std::{i32, i64};
+
+    #[test]
+    fn test_duration() {
+        assert!(Duration::seconds(1) != Duration::zero());
+        assert_eq!(Duration::seconds(1) + Duration::seconds(2), Duration::seconds(3));
+        assert_eq!(
+            Duration::seconds(86399) + Duration::seconds(4),
+            Duration::days(1) + Duration::seconds(3)
+        );
+        assert_eq!(Duration::days(10) - Duration::seconds(1000), Duration::seconds(863000));
+        assert_eq!(Duration::days(10) - Duration::seconds(1000000), Duration::seconds(-136000));
+        assert_eq!(
+            Duration::days(2) + Duration::seconds(86399) + Duration::nanoseconds(1234567890),
+            Duration::days(3) + Duration::nanoseconds(234567890)
+        );
+        assert_eq!(-Duration::days(3), Duration::days(-3));
+        assert_eq!(
+            -(Duration::days(3) + Duration::seconds(70)),
+            Duration::days(-4) + Duration::seconds(86400 - 70)
+        );
+    }
+
+    #[test]
+    fn test_duration_num_days() {
+        assert_eq!(Duration::zero().num_days(), 0);
+        assert_eq!(Duration::days(1).num_days(), 1);
+        assert_eq!(Duration::days(-1).num_days(), -1);
+        assert_eq!(Duration::seconds(86399).num_days(), 0);
+        assert_eq!(Duration::seconds(86401).num_days(), 1);
+        assert_eq!(Duration::seconds(-86399).num_days(), 0);
+        assert_eq!(Duration::seconds(-86401).num_days(), -1);
+        assert_eq!(Duration::days(i32::MAX as i64).num_days(), i32::MAX as i64);
+        assert_eq!(Duration::days(i32::MIN as i64).num_days(), i32::MIN as i64);
+    }
+
+    #[test]
+    fn test_duration_num_seconds() {
+        assert_eq!(Duration::zero().num_seconds(), 0);
+        assert_eq!(Duration::seconds(1).num_seconds(), 1);
+        assert_eq!(Duration::seconds(-1).num_seconds(), -1);
+        assert_eq!(Duration::milliseconds(999).num_seconds(), 0);
+        assert_eq!(Duration::milliseconds(1001).num_seconds(), 1);
+        assert_eq!(Duration::milliseconds(-999).num_seconds(), 0);
+        assert_eq!(Duration::milliseconds(-1001).num_seconds(), -1);
+    }
+
+    #[test]
+    fn test_duration_num_milliseconds() {
+        assert_eq!(Duration::zero().num_milliseconds(), 0);
+        assert_eq!(Duration::milliseconds(1).num_milliseconds(), 1);
+        assert_eq!(Duration::milliseconds(-1).num_milliseconds(), -1);
+        assert_eq!(Duration::microseconds(999).num_milliseconds(), 0);
+        assert_eq!(Duration::microseconds(1001).num_milliseconds(), 1);
+        assert_eq!(Duration::microseconds(-999).num_milliseconds(), 0);
+        assert_eq!(Duration::microseconds(-1001).num_milliseconds(), -1);
+        assert_eq!(Duration::milliseconds(i64::MAX).num_milliseconds(), i64::MAX);
+        assert_eq!(Duration::milliseconds(i64::MIN).num_milliseconds(), i64::MIN);
+        assert_eq!(MAX.num_milliseconds(), i64::MAX);
+        assert_eq!(MIN.num_milliseconds(), i64::MIN);
+    }
+
+    #[test]
+    fn test_duration_num_microseconds() {
+        assert_eq!(Duration::zero().num_microseconds(), Some(0));
+        assert_eq!(Duration::microseconds(1).num_microseconds(), Some(1));
+        assert_eq!(Duration::microseconds(-1).num_microseconds(), Some(-1));
+        assert_eq!(Duration::nanoseconds(999).num_microseconds(), Some(0));
+        assert_eq!(Duration::nanoseconds(1001).num_microseconds(), Some(1));
+        assert_eq!(Duration::nanoseconds(-999).num_microseconds(), Some(0));
+        assert_eq!(Duration::nanoseconds(-1001).num_microseconds(), Some(-1));
+        assert_eq!(Duration::microseconds(i64::MAX).num_microseconds(), Some(i64::MAX));
+        assert_eq!(Duration::microseconds(i64::MIN).num_microseconds(), Some(i64::MIN));
+        assert_eq!(MAX.num_microseconds(), None);
+        assert_eq!(MIN.num_microseconds(), None);
+
+        // overflow checks
+        const MICROS_PER_DAY: i64 = 86400_000_000;
+        assert_eq!(
+            Duration::days(i64::MAX / MICROS_PER_DAY).num_microseconds(),
+            Some(i64::MAX / MICROS_PER_DAY * MICROS_PER_DAY)
+        );
+        assert_eq!(
+            Duration::days(i64::MIN / MICROS_PER_DAY).num_microseconds(),
+            Some(i64::MIN / MICROS_PER_DAY * MICROS_PER_DAY)
+        );
+        assert_eq!(Duration::days(i64::MAX / MICROS_PER_DAY + 1).num_microseconds(), None);
+        assert_eq!(Duration::days(i64::MIN / MICROS_PER_DAY - 1).num_microseconds(), None);
+    }
+
+    #[test]
+    fn test_duration_num_nanoseconds() {
+        assert_eq!(Duration::zero().num_nanoseconds(), Some(0));
+        assert_eq!(Duration::nanoseconds(1).num_nanoseconds(), Some(1));
+        assert_eq!(Duration::nanoseconds(-1).num_nanoseconds(), Some(-1));
+        assert_eq!(Duration::nanoseconds(i64::MAX).num_nanoseconds(), Some(i64::MAX));
+        assert_eq!(Duration::nanoseconds(i64::MIN).num_nanoseconds(), Some(i64::MIN));
+        assert_eq!(MAX.num_nanoseconds(), None);
+        assert_eq!(MIN.num_nanoseconds(), None);
+
+        // overflow checks
+        const NANOS_PER_DAY: i64 = 86400_000_000_000;
+        assert_eq!(
+            Duration::days(i64::MAX / NANOS_PER_DAY).num_nanoseconds(),
+            Some(i64::MAX / NANOS_PER_DAY * NANOS_PER_DAY)
+        );
+        assert_eq!(
+            Duration::days(i64::MIN / NANOS_PER_DAY).num_nanoseconds(),
+            Some(i64::MIN / NANOS_PER_DAY * NANOS_PER_DAY)
+        );
+        assert_eq!(Duration::days(i64::MAX / NANOS_PER_DAY + 1).num_nanoseconds(), None);
+        assert_eq!(Duration::days(i64::MIN / NANOS_PER_DAY - 1).num_nanoseconds(), None);
+    }
+
+    #[test]
+    fn test_duration_checked_ops() {
+        assert_eq!(
+            Duration::milliseconds(i64::MAX - 1).checked_add(&Duration::microseconds(999)),
+            Some(Duration::milliseconds(i64::MAX - 2) + Duration::microseconds(1999))
+        );
+        assert!(Duration::milliseconds(i64::MAX)
+            .checked_add(&Duration::microseconds(1000))
+            .is_none());
+
+        assert_eq!(
+            Duration::milliseconds(i64::MIN).checked_sub(&Duration::milliseconds(0)),
+            Some(Duration::milliseconds(i64::MIN))
+        );
+        assert!(Duration::milliseconds(i64::MIN).checked_sub(&Duration::milliseconds(1)).is_none());
+    }
+
+    #[test]
+    fn test_duration_abs() {
+        assert_eq!(Duration::milliseconds(1300).abs(), Duration::milliseconds(1300));
+        assert_eq!(Duration::milliseconds(1000).abs(), Duration::milliseconds(1000));
+        assert_eq!(Duration::milliseconds(300).abs(), Duration::milliseconds(300));
+        assert_eq!(Duration::milliseconds(0).abs(), Duration::milliseconds(0));
+        assert_eq!(Duration::milliseconds(-300).abs(), Duration::milliseconds(300));
+        assert_eq!(Duration::milliseconds(-700).abs(), Duration::milliseconds(700));
+        assert_eq!(Duration::milliseconds(-1000).abs(), Duration::milliseconds(1000));
+        assert_eq!(Duration::milliseconds(-1300).abs(), Duration::milliseconds(1300));
+        assert_eq!(Duration::milliseconds(-1700).abs(), Duration::milliseconds(1700));
+    }
+
+    #[test]
+    fn test_duration_mul() {
+        assert_eq!(Duration::zero() * i32::MAX, Duration::zero());
+        assert_eq!(Duration::zero() * i32::MIN, Duration::zero());
+        assert_eq!(Duration::nanoseconds(1) * 0, Duration::zero());
+        assert_eq!(Duration::nanoseconds(1) * 1, Duration::nanoseconds(1));
+        assert_eq!(Duration::nanoseconds(1) * 1_000_000_000, Duration::seconds(1));
+        assert_eq!(Duration::nanoseconds(1) * -1_000_000_000, -Duration::seconds(1));
+        assert_eq!(-Duration::nanoseconds(1) * 1_000_000_000, -Duration::seconds(1));
+        assert_eq!(
+            Duration::nanoseconds(30) * 333_333_333,
+            Duration::seconds(10) - Duration::nanoseconds(10)
+        );
+        assert_eq!(
+            (Duration::nanoseconds(1) + Duration::seconds(1) + Duration::days(1)) * 3,
+            Duration::nanoseconds(3) + Duration::seconds(3) + Duration::days(3)
+        );
+        assert_eq!(Duration::milliseconds(1500) * -2, Duration::seconds(-3));
+        assert_eq!(Duration::milliseconds(-1500) * 2, Duration::seconds(-3));
+    }
+
+    #[test]
+    fn test_duration_div() {
+        assert_eq!(Duration::zero() / i32::MAX, Duration::zero());
+        assert_eq!(Duration::zero() / i32::MIN, Duration::zero());
+        assert_eq!(Duration::nanoseconds(123_456_789) / 1, Duration::nanoseconds(123_456_789));
+        assert_eq!(Duration::nanoseconds(123_456_789) / -1, -Duration::nanoseconds(123_456_789));
+        assert_eq!(-Duration::nanoseconds(123_456_789) / -1, Duration::nanoseconds(123_456_789));
+        assert_eq!(-Duration::nanoseconds(123_456_789) / 1, -Duration::nanoseconds(123_456_789));
+        assert_eq!(Duration::seconds(1) / 3, Duration::nanoseconds(333_333_333));
+        assert_eq!(Duration::seconds(4) / 3, Duration::nanoseconds(1_333_333_333));
+        assert_eq!(Duration::seconds(-1) / 2, Duration::milliseconds(-500));
+        assert_eq!(Duration::seconds(1) / -2, Duration::milliseconds(-500));
+        assert_eq!(Duration::seconds(-1) / -2, Duration::milliseconds(500));
+        assert_eq!(Duration::seconds(-4) / 3, Duration::nanoseconds(-1_333_333_333));
+        assert_eq!(Duration::seconds(-4) / -3, Duration::nanoseconds(1_333_333_333));
+    }
+
+    #[test]
+    fn test_duration_sum() {
+        let duration_list_1 = [Duration::zero(), Duration::seconds(1)];
+        let sum_1: Duration = duration_list_1.iter().sum();
+        assert_eq!(sum_1, Duration::seconds(1));
+
+        let duration_list_2 =
+            [Duration::zero(), Duration::seconds(1), Duration::seconds(6), Duration::seconds(10)];
+        let sum_2: Duration = duration_list_2.iter().sum();
+        assert_eq!(sum_2, Duration::seconds(17));
+
+        let duration_vec = vec![
+            Duration::zero(),
+            Duration::seconds(1),
+            Duration::seconds(6),
+            Duration::seconds(10),
+        ];
+        let sum_3: Duration = duration_vec.into_iter().sum();
+        assert_eq!(sum_3, Duration::seconds(17));
+    }
+
+    #[test]
+    fn test_duration_fmt() {
+        assert_eq!(Duration::zero().to_string(), "PT0S");
+        assert_eq!(Duration::days(42).to_string(), "P42D");
+        assert_eq!(Duration::days(-42).to_string(), "-P42D");
+        assert_eq!(Duration::seconds(42).to_string(), "PT42S");
+        assert_eq!(Duration::milliseconds(42).to_string(), "PT0.042S");
+        assert_eq!(Duration::microseconds(42).to_string(), "PT0.000042S");
+        assert_eq!(Duration::nanoseconds(42).to_string(), "PT0.000000042S");
+        assert_eq!((Duration::days(7) + Duration::milliseconds(6543)).to_string(), "P7DT6.543S");
+        assert_eq!(Duration::seconds(-86401).to_string(), "-P1DT1S");
+        assert_eq!(Duration::nanoseconds(-1).to_string(), "-PT0.000000001S");
+
+        // the format specifier should have no effect on `Duration`
+        assert_eq!(
+            format!("{:30}", Duration::days(1) + Duration::milliseconds(2345)),
+            "P1DT2.345S"
+        );
+    }
+
+    #[test]
+    fn test_to_std() {
+        assert_eq!(Duration::seconds(1).to_std(), Ok(StdDuration::new(1, 0)));
+        assert_eq!(Duration::seconds(86401).to_std(), Ok(StdDuration::new(86401, 0)));
+        assert_eq!(Duration::milliseconds(123).to_std(), Ok(StdDuration::new(0, 123000000)));
+        assert_eq!(Duration::milliseconds(123765).to_std(), Ok(StdDuration::new(123, 765000000)));
+        assert_eq!(Duration::nanoseconds(777).to_std(), Ok(StdDuration::new(0, 777)));
+        assert_eq!(MAX.to_std(), Ok(StdDuration::new(9223372036854775, 807000000)));
+        assert_eq!(Duration::seconds(-1).to_std(), Err(OutOfRangeError(())));
+        assert_eq!(Duration::milliseconds(-1).to_std(), Err(OutOfRangeError(())));
+    }
+
+    #[test]
+    fn test_from_std() {
+        assert_eq!(Ok(Duration::seconds(1)), Duration::from_std(StdDuration::new(1, 0)));
+        assert_eq!(Ok(Duration::seconds(86401)), Duration::from_std(StdDuration::new(86401, 0)));
+        assert_eq!(
+            Ok(Duration::milliseconds(123)),
+            Duration::from_std(StdDuration::new(0, 123000000))
+        );
+        assert_eq!(
+            Ok(Duration::milliseconds(123765)),
+            Duration::from_std(StdDuration::new(123, 765000000))
+        );
+        assert_eq!(Ok(Duration::nanoseconds(777)), Duration::from_std(StdDuration::new(0, 777)));
+        assert_eq!(Ok(MAX), Duration::from_std(StdDuration::new(9223372036854775, 807000000)));
+        assert_eq!(
+            Duration::from_std(StdDuration::new(9223372036854776, 0)),
+            Err(OutOfRangeError(()))
+        );
+        assert_eq!(
+            Duration::from_std(StdDuration::new(9223372036854775, 807000001)),
+            Err(OutOfRangeError(()))
+        );
+    }
+}

javascript-engine/external/chrono/src/round.rs

@@ -0,0 +1,763 @@
+// This is a part of Chrono.
+// See README.md and LICENSE.txt for details.
+
+use crate::datetime::DateTime;
+use crate::oldtime::Duration;
+use crate::NaiveDateTime;
+use crate::TimeZone;
+use crate::Timelike;
+use core::cmp::Ordering;
+use core::fmt;
+use core::marker::Sized;
+use core::ops::{Add, Sub};
+
+/// Extension trait for subsecond rounding or truncation to a maximum number
+/// of digits. Rounding can be used to decrease the error variance when
+/// serializing/persisting to lower precision. Truncation is the default
+/// behavior in Chrono display formatting.  Either can be used to guarantee
+/// equality (e.g. for testing) when round-tripping through a lower precision
+/// format.
+pub trait SubsecRound {
+    /// Return a copy rounded to the specified number of subsecond digits. With
+    /// 9 or more digits, self is returned unmodified. Halfway values are
+    /// rounded up (away from zero).
+    ///
+    /// # Example
+    /// ``` rust
+    /// # use chrono::{DateTime, SubsecRound, Timelike, TimeZone, Utc, NaiveDate};
+    /// let dt = NaiveDate::from_ymd_opt(2018, 1, 11).unwrap().and_hms_milli_opt(12, 0, 0, 154).unwrap().and_local_timezone(Utc).unwrap();
+    /// assert_eq!(dt.round_subsecs(2).nanosecond(), 150_000_000);
+    /// assert_eq!(dt.round_subsecs(1).nanosecond(), 200_000_000);
+    /// ```
+    fn round_subsecs(self, digits: u16) -> Self;
+
+    /// Return a copy truncated to the specified number of subsecond
+    /// digits. With 9 or more digits, self is returned unmodified.
+    ///
+    /// # Example
+    /// ``` rust
+    /// # use chrono::{DateTime, SubsecRound, Timelike, TimeZone, Utc, NaiveDate};
+    /// let dt = NaiveDate::from_ymd_opt(2018, 1, 11).unwrap().and_hms_milli_opt(12, 0, 0, 154).unwrap().and_local_timezone(Utc).unwrap();
+    /// assert_eq!(dt.trunc_subsecs(2).nanosecond(), 150_000_000);
+    /// assert_eq!(dt.trunc_subsecs(1).nanosecond(), 100_000_000);
+    /// ```
+    fn trunc_subsecs(self, digits: u16) -> Self;
+}
+
+impl<T> SubsecRound for T
+where
+    T: Timelike + Add<Duration, Output = T> + Sub<Duration, Output = T>,
+{
+    fn round_subsecs(self, digits: u16) -> T {
+        let span = span_for_digits(digits);
+        let delta_down = self.nanosecond() % span;
+        if delta_down > 0 {
+            let delta_up = span - delta_down;
+            if delta_up <= delta_down {
+                self + Duration::nanoseconds(delta_up.into())
+            } else {
+                self - Duration::nanoseconds(delta_down.into())
+            }
+        } else {
+            self // unchanged
+        }
+    }
+
+    fn trunc_subsecs(self, digits: u16) -> T {
+        let span = span_for_digits(digits);
+        let delta_down = self.nanosecond() % span;
+        if delta_down > 0 {
+            self - Duration::nanoseconds(delta_down.into())
+        } else {
+            self // unchanged
+        }
+    }
+}
+
+// Return the maximum span in nanoseconds for the target number of digits.
+fn span_for_digits(digits: u16) -> u32 {
+    // fast lookup form of: 10^(9-min(9,digits))
+    match digits {
+        0 => 1_000_000_000,
+        1 => 100_000_000,
+        2 => 10_000_000,
+        3 => 1_000_000,
+        4 => 100_000,
+        5 => 10_000,
+        6 => 1_000,
+        7 => 100,
+        8 => 10,
+        _ => 1,
+    }
+}
+
+/// Extension trait for rounding or truncating a DateTime by a Duration.
+///
+/// # Limitations
+/// Both rounding and truncating are done via [`Duration::num_nanoseconds`] and
+/// [`DateTime::timestamp_nanos`]. This means that they will fail if either the
+/// `Duration` or the `DateTime` are too big to represented as nanoseconds. They
+/// will also fail if the `Duration` is bigger than the timestamp.
+pub trait DurationRound: Sized {
+    /// Error that can occur in rounding or truncating
+    #[cfg(any(feature = "std", test))]
+    type Err: std::error::Error;
+
+    /// Error that can occur in rounding or truncating
+    #[cfg(not(any(feature = "std", test)))]
+    type Err: fmt::Debug + fmt::Display;
+
+    /// Return a copy rounded by Duration.
+    ///
+    /// # Example
+    /// ``` rust
+    /// # use chrono::{DateTime, DurationRound, Duration, TimeZone, Utc, NaiveDate};
+    /// let dt = NaiveDate::from_ymd_opt(2018, 1, 11).unwrap().and_hms_milli_opt(12, 0, 0, 154).unwrap().and_local_timezone(Utc).unwrap();
+    /// assert_eq!(
+    ///     dt.duration_round(Duration::milliseconds(10)).unwrap().to_string(),
+    ///     "2018-01-11 12:00:00.150 UTC"
+    /// );
+    /// assert_eq!(
+    ///     dt.duration_round(Duration::days(1)).unwrap().to_string(),
+    ///     "2018-01-12 00:00:00 UTC"
+    /// );
+    /// ```
+    fn duration_round(self, duration: Duration) -> Result<Self, Self::Err>;
+
+    /// Return a copy truncated by Duration.
+    ///
+    /// # Example
+    /// ``` rust
+    /// # use chrono::{DateTime, DurationRound, Duration, TimeZone, Utc, NaiveDate};
+    /// let dt = NaiveDate::from_ymd_opt(2018, 1, 11).unwrap().and_hms_milli_opt(12, 0, 0, 154).unwrap().and_local_timezone(Utc).unwrap();
+    /// assert_eq!(
+    ///     dt.duration_trunc(Duration::milliseconds(10)).unwrap().to_string(),
+    ///     "2018-01-11 12:00:00.150 UTC"
+    /// );
+    /// assert_eq!(
+    ///     dt.duration_trunc(Duration::days(1)).unwrap().to_string(),
+    ///     "2018-01-11 00:00:00 UTC"
+    /// );
+    /// ```
+    fn duration_trunc(self, duration: Duration) -> Result<Self, Self::Err>;
+}
+
+/// The maximum number of seconds a DateTime can be to be represented as nanoseconds
+const MAX_SECONDS_TIMESTAMP_FOR_NANOS: i64 = 9_223_372_036;
+
+impl<Tz: TimeZone> DurationRound for DateTime<Tz> {
+    type Err = RoundingError;
+
+    fn duration_round(self, duration: Duration) -> Result<Self, Self::Err> {
+        duration_round(self.naive_local(), self, duration)
+    }
+
+    fn duration_trunc(self, duration: Duration) -> Result<Self, Self::Err> {
+        duration_trunc(self.naive_local(), self, duration)
+    }
+}
+
+impl DurationRound for NaiveDateTime {
+    type Err = RoundingError;
+
+    fn duration_round(self, duration: Duration) -> Result<Self, Self::Err> {
+        duration_round(self, self, duration)
+    }
+
+    fn duration_trunc(self, duration: Duration) -> Result<Self, Self::Err> {
+        duration_trunc(self, self, duration)
+    }
+}
+
+fn duration_round<T>(
+    naive: NaiveDateTime,
+    original: T,
+    duration: Duration,
+) -> Result<T, RoundingError>
+where
+    T: Timelike + Add<Duration, Output = T> + Sub<Duration, Output = T>,
+{
+    if let Some(span) = duration.num_nanoseconds() {
+        if naive.timestamp().abs() > MAX_SECONDS_TIMESTAMP_FOR_NANOS {
+            return Err(RoundingError::TimestampExceedsLimit);
+        }
+        let stamp = naive.timestamp_nanos();
+        if span > stamp.abs() {
+            return Err(RoundingError::DurationExceedsTimestamp);
+        }
+        if span == 0 {
+            return Ok(original);
+        }
+        let delta_down = stamp % span;
+        if delta_down == 0 {
+            Ok(original)
+        } else {
+            let (delta_up, delta_down) = if delta_down < 0 {
+                (delta_down.abs(), span - delta_down.abs())
+            } else {
+                (span - delta_down, delta_down)
+            };
+            if delta_up <= delta_down {
+                Ok(original + Duration::nanoseconds(delta_up))
+            } else {
+                Ok(original - Duration::nanoseconds(delta_down))
+            }
+        }
+    } else {
+        Err(RoundingError::DurationExceedsLimit)
+    }
+}
+
+fn duration_trunc<T>(
+    naive: NaiveDateTime,
+    original: T,
+    duration: Duration,
+) -> Result<T, RoundingError>
+where
+    T: Timelike + Add<Duration, Output = T> + Sub<Duration, Output = T>,
+{
+    if let Some(span) = duration.num_nanoseconds() {
+        if naive.timestamp().abs() > MAX_SECONDS_TIMESTAMP_FOR_NANOS {
+            return Err(RoundingError::TimestampExceedsLimit);
+        }
+        let stamp = naive.timestamp_nanos();
+        if span > stamp.abs() {
+            return Err(RoundingError::DurationExceedsTimestamp);
+        }
+        let delta_down = stamp % span;
+        match delta_down.cmp(&0) {
+            Ordering::Equal => Ok(original),
+            Ordering::Greater => Ok(original - Duration::nanoseconds(delta_down)),
+            Ordering::Less => Ok(original - Duration::nanoseconds(span - delta_down.abs())),
+        }
+    } else {
+        Err(RoundingError::DurationExceedsLimit)
+    }
+}
+
+/// An error from rounding by `Duration`
+///
+/// See: [`DurationRound`]
+#[derive(Debug, Clone, PartialEq, Eq, Copy)]
+pub enum RoundingError {
+    /// Error when the Duration exceeds the Duration from or until the Unix epoch.
+    ///
+    /// ``` rust
+    /// # use chrono::{DateTime, DurationRound, Duration, RoundingError, TimeZone, Utc};
+    /// let dt = Utc.with_ymd_and_hms(1970, 12, 12, 0, 0, 0).unwrap();
+    ///
+    /// assert_eq!(
+    ///     dt.duration_round(Duration::days(365)),
+    ///     Err(RoundingError::DurationExceedsTimestamp),
+    /// );
+    /// ```
+    DurationExceedsTimestamp,
+
+    /// Error when `Duration.num_nanoseconds` exceeds the limit.
+    ///
+    /// ``` rust
+    /// # use chrono::{DateTime, DurationRound, Duration, RoundingError, TimeZone, Utc, NaiveDate};
+    /// let dt = NaiveDate::from_ymd_opt(2260, 12, 31).unwrap().and_hms_nano_opt(23, 59, 59, 1_75_500_000).unwrap().and_local_timezone(Utc).unwrap();
+    ///
+    /// assert_eq!(
+    ///     dt.duration_round(Duration::days(300 * 365)),
+    ///     Err(RoundingError::DurationExceedsLimit)
+    /// );
+    /// ```
+    DurationExceedsLimit,
+
+    /// Error when `DateTime.timestamp_nanos` exceeds the limit.
+    ///
+    /// ``` rust
+    /// # use chrono::{DateTime, DurationRound, Duration, RoundingError, TimeZone, Utc};
+    /// let dt = Utc.with_ymd_and_hms(2300, 12, 12, 0, 0, 0).unwrap();
+    ///
+    /// assert_eq!(dt.duration_round(Duration::days(1)), Err(RoundingError::TimestampExceedsLimit),);
+    /// ```
+    TimestampExceedsLimit,
+}
+
+impl fmt::Display for RoundingError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            RoundingError::DurationExceedsTimestamp => {
+                write!(f, "duration in nanoseconds exceeds timestamp")
+            }
+            RoundingError::DurationExceedsLimit => {
+                write!(f, "duration exceeds num_nanoseconds limit")
+            }
+            RoundingError::TimestampExceedsLimit => {
+                write!(f, "timestamp exceeds num_nanoseconds limit")
+            }
+        }
+    }
+}
+
+#[cfg(any(feature = "std", test))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+impl std::error::Error for RoundingError {
+    #[allow(deprecated)]
+    fn description(&self) -> &str {
+        "error from rounding or truncating with DurationRound"
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{Duration, DurationRound, SubsecRound};
+    use crate::offset::{FixedOffset, TimeZone, Utc};
+    use crate::NaiveDate;
+    use crate::Timelike;
+
+    #[test]
+    fn test_round_subsecs() {
+        let pst = FixedOffset::east_opt(8 * 60 * 60).unwrap();
+        let dt = pst
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2018, 1, 11)
+                    .unwrap()
+                    .and_hms_nano_opt(10, 5, 13, 84_660_684)
+                    .unwrap(),
+            )
+            .unwrap();
+
+        assert_eq!(dt.round_subsecs(10), dt);
+        assert_eq!(dt.round_subsecs(9), dt);
+        assert_eq!(dt.round_subsecs(8).nanosecond(), 84_660_680);
+        assert_eq!(dt.round_subsecs(7).nanosecond(), 84_660_700);
+        assert_eq!(dt.round_subsecs(6).nanosecond(), 84_661_000);
+        assert_eq!(dt.round_subsecs(5).nanosecond(), 84_660_000);
+        assert_eq!(dt.round_subsecs(4).nanosecond(), 84_700_000);
+        assert_eq!(dt.round_subsecs(3).nanosecond(), 85_000_000);
+        assert_eq!(dt.round_subsecs(2).nanosecond(), 80_000_000);
+        assert_eq!(dt.round_subsecs(1).nanosecond(), 100_000_000);
+
+        assert_eq!(dt.round_subsecs(0).nanosecond(), 0);
+        assert_eq!(dt.round_subsecs(0).second(), 13);
+
+        let dt = Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2018, 1, 11)
+                    .unwrap()
+                    .and_hms_nano_opt(10, 5, 27, 750_500_000)
+                    .unwrap(),
+            )
+            .unwrap();
+        assert_eq!(dt.round_subsecs(9), dt);
+        assert_eq!(dt.round_subsecs(4), dt);
+        assert_eq!(dt.round_subsecs(3).nanosecond(), 751_000_000);
+        assert_eq!(dt.round_subsecs(2).nanosecond(), 750_000_000);
+        assert_eq!(dt.round_subsecs(1).nanosecond(), 800_000_000);
+
+        assert_eq!(dt.round_subsecs(0).nanosecond(), 0);
+        assert_eq!(dt.round_subsecs(0).second(), 28);
+    }
+
+    #[test]
+    fn test_round_leap_nanos() {
+        let dt = Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2016, 12, 31)
+                    .unwrap()
+                    .and_hms_nano_opt(23, 59, 59, 1_750_500_000)
+                    .unwrap(),
+            )
+            .unwrap();
+        assert_eq!(dt.round_subsecs(9), dt);
+        assert_eq!(dt.round_subsecs(4), dt);
+        assert_eq!(dt.round_subsecs(2).nanosecond(), 1_750_000_000);
+        assert_eq!(dt.round_subsecs(1).nanosecond(), 1_800_000_000);
+        assert_eq!(dt.round_subsecs(1).second(), 59);
+
+        assert_eq!(dt.round_subsecs(0).nanosecond(), 0);
+        assert_eq!(dt.round_subsecs(0).second(), 0);
+    }
+
+    #[test]
+    fn test_trunc_subsecs() {
+        let pst = FixedOffset::east_opt(8 * 60 * 60).unwrap();
+        let dt = pst
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2018, 1, 11)
+                    .unwrap()
+                    .and_hms_nano_opt(10, 5, 13, 84_660_684)
+                    .unwrap(),
+            )
+            .unwrap();
+
+        assert_eq!(dt.trunc_subsecs(10), dt);
+        assert_eq!(dt.trunc_subsecs(9), dt);
+        assert_eq!(dt.trunc_subsecs(8).nanosecond(), 84_660_680);
+        assert_eq!(dt.trunc_subsecs(7).nanosecond(), 84_660_600);
+        assert_eq!(dt.trunc_subsecs(6).nanosecond(), 84_660_000);
+        assert_eq!(dt.trunc_subsecs(5).nanosecond(), 84_660_000);
+        assert_eq!(dt.trunc_subsecs(4).nanosecond(), 84_600_000);
+        assert_eq!(dt.trunc_subsecs(3).nanosecond(), 84_000_000);
+        assert_eq!(dt.trunc_subsecs(2).nanosecond(), 80_000_000);
+        assert_eq!(dt.trunc_subsecs(1).nanosecond(), 0);
+
+        assert_eq!(dt.trunc_subsecs(0).nanosecond(), 0);
+        assert_eq!(dt.trunc_subsecs(0).second(), 13);
+
+        let dt = pst
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2018, 1, 11)
+                    .unwrap()
+                    .and_hms_nano_opt(10, 5, 27, 750_500_000)
+                    .unwrap(),
+            )
+            .unwrap();
+        assert_eq!(dt.trunc_subsecs(9), dt);
+        assert_eq!(dt.trunc_subsecs(4), dt);
+        assert_eq!(dt.trunc_subsecs(3).nanosecond(), 750_000_000);
+        assert_eq!(dt.trunc_subsecs(2).nanosecond(), 750_000_000);
+        assert_eq!(dt.trunc_subsecs(1).nanosecond(), 700_000_000);
+
+        assert_eq!(dt.trunc_subsecs(0).nanosecond(), 0);
+        assert_eq!(dt.trunc_subsecs(0).second(), 27);
+    }
+
+    #[test]
+    fn test_trunc_leap_nanos() {
+        let dt = Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2016, 12, 31)
+                    .unwrap()
+                    .and_hms_nano_opt(23, 59, 59, 1_750_500_000)
+                    .unwrap(),
+            )
+            .unwrap();
+        assert_eq!(dt.trunc_subsecs(9), dt);
+        assert_eq!(dt.trunc_subsecs(4), dt);
+        assert_eq!(dt.trunc_subsecs(2).nanosecond(), 1_750_000_000);
+        assert_eq!(dt.trunc_subsecs(1).nanosecond(), 1_700_000_000);
+        assert_eq!(dt.trunc_subsecs(1).second(), 59);
+
+        assert_eq!(dt.trunc_subsecs(0).nanosecond(), 1_000_000_000);
+        assert_eq!(dt.trunc_subsecs(0).second(), 59);
+    }
+
+    #[test]
+    fn test_duration_round() {
+        let dt = Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2016, 12, 31)
+                    .unwrap()
+                    .and_hms_nano_opt(23, 59, 59, 175_500_000)
+                    .unwrap(),
+            )
+            .unwrap();
+
+        assert_eq!(
+            dt.duration_round(Duration::zero()).unwrap().to_string(),
+            "2016-12-31 23:59:59.175500 UTC"
+        );
+
+        assert_eq!(
+            dt.duration_round(Duration::milliseconds(10)).unwrap().to_string(),
+            "2016-12-31 23:59:59.180 UTC"
+        );
+
+        // round up
+        let dt = Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2012, 12, 12)
+                    .unwrap()
+                    .and_hms_milli_opt(18, 22, 30, 0)
+                    .unwrap(),
+            )
+            .unwrap();
+        assert_eq!(
+            dt.duration_round(Duration::minutes(5)).unwrap().to_string(),
+            "2012-12-12 18:25:00 UTC"
+        );
+        // round down
+        let dt = Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2012, 12, 12)
+                    .unwrap()
+                    .and_hms_milli_opt(18, 22, 29, 999)
+                    .unwrap(),
+            )
+            .unwrap();
+        assert_eq!(
+            dt.duration_round(Duration::minutes(5)).unwrap().to_string(),
+            "2012-12-12 18:20:00 UTC"
+        );
+
+        assert_eq!(
+            dt.duration_round(Duration::minutes(10)).unwrap().to_string(),
+            "2012-12-12 18:20:00 UTC"
+        );
+        assert_eq!(
+            dt.duration_round(Duration::minutes(30)).unwrap().to_string(),
+            "2012-12-12 18:30:00 UTC"
+        );
+        assert_eq!(
+            dt.duration_round(Duration::hours(1)).unwrap().to_string(),
+            "2012-12-12 18:00:00 UTC"
+        );
+        assert_eq!(
+            dt.duration_round(Duration::days(1)).unwrap().to_string(),
+            "2012-12-13 00:00:00 UTC"
+        );
+
+        // timezone east
+        let dt =
+            FixedOffset::east_opt(3600).unwrap().with_ymd_and_hms(2020, 10, 27, 15, 0, 0).unwrap();
+        assert_eq!(
+            dt.duration_round(Duration::days(1)).unwrap().to_string(),
+            "2020-10-28 00:00:00 +01:00"
+        );
+        assert_eq!(
+            dt.duration_round(Duration::weeks(1)).unwrap().to_string(),
+            "2020-10-29 00:00:00 +01:00"
+        );
+
+        // timezone west
+        let dt =
+            FixedOffset::west_opt(3600).unwrap().with_ymd_and_hms(2020, 10, 27, 15, 0, 0).unwrap();
+        assert_eq!(
+            dt.duration_round(Duration::days(1)).unwrap().to_string(),
+            "2020-10-28 00:00:00 -01:00"
+        );
+        assert_eq!(
+            dt.duration_round(Duration::weeks(1)).unwrap().to_string(),
+            "2020-10-29 00:00:00 -01:00"
+        );
+    }
+
+    #[test]
+    fn test_duration_round_naive() {
+        let dt = Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2016, 12, 31)
+                    .unwrap()
+                    .and_hms_nano_opt(23, 59, 59, 175_500_000)
+                    .unwrap(),
+            )
+            .unwrap()
+            .naive_utc();
+
+        assert_eq!(
+            dt.duration_round(Duration::zero()).unwrap().to_string(),
+            "2016-12-31 23:59:59.175500"
+        );
+
+        assert_eq!(
+            dt.duration_round(Duration::milliseconds(10)).unwrap().to_string(),
+            "2016-12-31 23:59:59.180"
+        );
+
+        // round up
+        let dt = Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2012, 12, 12)
+                    .unwrap()
+                    .and_hms_milli_opt(18, 22, 30, 0)
+                    .unwrap(),
+            )
+            .unwrap()
+            .naive_utc();
+        assert_eq!(
+            dt.duration_round(Duration::minutes(5)).unwrap().to_string(),
+            "2012-12-12 18:25:00"
+        );
+        // round down
+        let dt = Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2012, 12, 12)
+                    .unwrap()
+                    .and_hms_milli_opt(18, 22, 29, 999)
+                    .unwrap(),
+            )
+            .unwrap()
+            .naive_utc();
+        assert_eq!(
+            dt.duration_round(Duration::minutes(5)).unwrap().to_string(),
+            "2012-12-12 18:20:00"
+        );
+
+        assert_eq!(
+            dt.duration_round(Duration::minutes(10)).unwrap().to_string(),
+            "2012-12-12 18:20:00"
+        );
+        assert_eq!(
+            dt.duration_round(Duration::minutes(30)).unwrap().to_string(),
+            "2012-12-12 18:30:00"
+        );
+        assert_eq!(
+            dt.duration_round(Duration::hours(1)).unwrap().to_string(),
+            "2012-12-12 18:00:00"
+        );
+        assert_eq!(
+            dt.duration_round(Duration::days(1)).unwrap().to_string(),
+            "2012-12-13 00:00:00"
+        );
+    }
+
+    #[test]
+    fn test_duration_round_pre_epoch() {
+        let dt = Utc.with_ymd_and_hms(1969, 12, 12, 12, 12, 12).unwrap();
+        assert_eq!(
+            dt.duration_round(Duration::minutes(10)).unwrap().to_string(),
+            "1969-12-12 12:10:00 UTC"
+        );
+    }
+
+    #[test]
+    fn test_duration_trunc() {
+        let dt = Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2016, 12, 31)
+                    .unwrap()
+                    .and_hms_nano_opt(23, 59, 59, 175_500_000)
+                    .unwrap(),
+            )
+            .unwrap();
+
+        assert_eq!(
+            dt.duration_trunc(Duration::milliseconds(10)).unwrap().to_string(),
+            "2016-12-31 23:59:59.170 UTC"
+        );
+
+        // would round up
+        let dt = Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2012, 12, 12)
+                    .unwrap()
+                    .and_hms_milli_opt(18, 22, 30, 0)
+                    .unwrap(),
+            )
+            .unwrap();
+        assert_eq!(
+            dt.duration_trunc(Duration::minutes(5)).unwrap().to_string(),
+            "2012-12-12 18:20:00 UTC"
+        );
+        // would round down
+        let dt = Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2012, 12, 12)
+                    .unwrap()
+                    .and_hms_milli_opt(18, 22, 29, 999)
+                    .unwrap(),
+            )
+            .unwrap();
+        assert_eq!(
+            dt.duration_trunc(Duration::minutes(5)).unwrap().to_string(),
+            "2012-12-12 18:20:00 UTC"
+        );
+        assert_eq!(
+            dt.duration_trunc(Duration::minutes(10)).unwrap().to_string(),
+            "2012-12-12 18:20:00 UTC"
+        );
+        assert_eq!(
+            dt.duration_trunc(Duration::minutes(30)).unwrap().to_string(),
+            "2012-12-12 18:00:00 UTC"
+        );
+        assert_eq!(
+            dt.duration_trunc(Duration::hours(1)).unwrap().to_string(),
+            "2012-12-12 18:00:00 UTC"
+        );
+        assert_eq!(
+            dt.duration_trunc(Duration::days(1)).unwrap().to_string(),
+            "2012-12-12 00:00:00 UTC"
+        );
+
+        // timezone east
+        let dt =
+            FixedOffset::east_opt(3600).unwrap().with_ymd_and_hms(2020, 10, 27, 15, 0, 0).unwrap();
+        assert_eq!(
+            dt.duration_trunc(Duration::days(1)).unwrap().to_string(),
+            "2020-10-27 00:00:00 +01:00"
+        );
+        assert_eq!(
+            dt.duration_trunc(Duration::weeks(1)).unwrap().to_string(),
+            "2020-10-22 00:00:00 +01:00"
+        );
+
+        // timezone west
+        let dt =
+            FixedOffset::west_opt(3600).unwrap().with_ymd_and_hms(2020, 10, 27, 15, 0, 0).unwrap();
+        assert_eq!(
+            dt.duration_trunc(Duration::days(1)).unwrap().to_string(),
+            "2020-10-27 00:00:00 -01:00"
+        );
+        assert_eq!(
+            dt.duration_trunc(Duration::weeks(1)).unwrap().to_string(),
+            "2020-10-22 00:00:00 -01:00"
+        );
+    }
+
+    #[test]
+    fn test_duration_trunc_naive() {
+        let dt = Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2016, 12, 31)
+                    .unwrap()
+                    .and_hms_nano_opt(23, 59, 59, 175_500_000)
+                    .unwrap(),
+            )
+            .unwrap()
+            .naive_utc();
+
+        assert_eq!(
+            dt.duration_trunc(Duration::milliseconds(10)).unwrap().to_string(),
+            "2016-12-31 23:59:59.170"
+        );
+
+        // would round up
+        let dt = Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2012, 12, 12)
+                    .unwrap()
+                    .and_hms_milli_opt(18, 22, 30, 0)
+                    .unwrap(),
+            )
+            .unwrap()
+            .naive_utc();
+        assert_eq!(
+            dt.duration_trunc(Duration::minutes(5)).unwrap().to_string(),
+            "2012-12-12 18:20:00"
+        );
+        // would round down
+        let dt = Utc
+            .from_local_datetime(
+                &NaiveDate::from_ymd_opt(2012, 12, 12)
+                    .unwrap()
+                    .and_hms_milli_opt(18, 22, 29, 999)
+                    .unwrap(),
+            )
+            .unwrap()
+            .naive_utc();
+        assert_eq!(
+            dt.duration_trunc(Duration::minutes(5)).unwrap().to_string(),
+            "2012-12-12 18:20:00"
+        );
+        assert_eq!(
+            dt.duration_trunc(Duration::minutes(10)).unwrap().to_string(),
+            "2012-12-12 18:20:00"
+        );
+        assert_eq!(
+            dt.duration_trunc(Duration::minutes(30)).unwrap().to_string(),
+            "2012-12-12 18:00:00"
+        );
+        assert_eq!(
+            dt.duration_trunc(Duration::hours(1)).unwrap().to_string(),
+            "2012-12-12 18:00:00"
+        );
+        assert_eq!(
+            dt.duration_trunc(Duration::days(1)).unwrap().to_string(),
+            "2012-12-12 00:00:00"
+        );
+    }
+
+    #[test]
+    fn test_duration_trunc_pre_epoch() {
+        let dt = Utc.with_ymd_and_hms(1969, 12, 12, 12, 12, 12).unwrap();
+        assert_eq!(
+            dt.duration_trunc(Duration::minutes(10)).unwrap().to_string(),
+            "1969-12-12 12:10:00 UTC"
+        );
+    }
+}

javascript-engine/external/chrono/src/traits.rs

@@ -0,0 +1,241 @@
+use crate::{IsoWeek, Weekday};
+
+/// The common set of methods for date component.
+pub trait Datelike: Sized {
+    /// Returns the year number in the [calendar date](./naive/struct.NaiveDate.html#calendar-date).
+    fn year(&self) -> i32;
+
+    /// Returns the absolute year number starting from 1 with a boolean flag,
+    /// which is false when the year predates the epoch (BCE/BC) and true otherwise (CE/AD).
+    #[inline]
+    fn year_ce(&self) -> (bool, u32) {
+        let year = self.year();
+        if year < 1 {
+            (false, (1 - year) as u32)
+        } else {
+            (true, year as u32)
+        }
+    }
+
+    /// Returns the month number starting from 1.
+    ///
+    /// The return value ranges from 1 to 12.
+    fn month(&self) -> u32;
+
+    /// Returns the month number starting from 0.
+    ///
+    /// The return value ranges from 0 to 11.
+    fn month0(&self) -> u32;
+
+    /// Returns the day of month starting from 1.
+    ///
+    /// The return value ranges from 1 to 31. (The last day of month differs by months.)
+    fn day(&self) -> u32;
+
+    /// Returns the day of month starting from 0.
+    ///
+    /// The return value ranges from 0 to 30. (The last day of month differs by months.)
+    fn day0(&self) -> u32;
+
+    /// Returns the day of year starting from 1.
+    ///
+    /// The return value ranges from 1 to 366. (The last day of year differs by years.)
+    fn ordinal(&self) -> u32;
+
+    /// Returns the day of year starting from 0.
+    ///
+    /// The return value ranges from 0 to 365. (The last day of year differs by years.)
+    fn ordinal0(&self) -> u32;
+
+    /// Returns the day of week.
+    fn weekday(&self) -> Weekday;
+
+    /// Returns the ISO week.
+    fn iso_week(&self) -> IsoWeek;
+
+    /// Makes a new value with the year number changed.
+    ///
+    /// Returns `None` when the resulting value would be invalid.
+    fn with_year(&self, year: i32) -> Option<Self>;
+
+    /// Makes a new value with the month number (starting from 1) changed.
+    ///
+    /// Returns `None` when the resulting value would be invalid.
+    fn with_month(&self, month: u32) -> Option<Self>;
+
+    /// Makes a new value with the month number (starting from 0) changed.
+    ///
+    /// Returns `None` when the resulting value would be invalid.
+    fn with_month0(&self, month0: u32) -> Option<Self>;
+
+    /// Makes a new value with the day of month (starting from 1) changed.
+    ///
+    /// Returns `None` when the resulting value would be invalid.
+    fn with_day(&self, day: u32) -> Option<Self>;
+
+    /// Makes a new value with the day of month (starting from 0) changed.
+    ///
+    /// Returns `None` when the resulting value would be invalid.
+    fn with_day0(&self, day0: u32) -> Option<Self>;
+
+    /// Makes a new value with the day of year (starting from 1) changed.
+    ///
+    /// Returns `None` when the resulting value would be invalid.
+    fn with_ordinal(&self, ordinal: u32) -> Option<Self>;
+
+    /// Makes a new value with the day of year (starting from 0) changed.
+    ///
+    /// Returns `None` when the resulting value would be invalid.
+    fn with_ordinal0(&self, ordinal0: u32) -> Option<Self>;
+
+    /// Counts the days in the proleptic Gregorian calendar, with January 1, Year 1 (CE) as day 1.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use chrono::{NaiveDate, Datelike};
+    ///
+    /// assert_eq!(NaiveDate::from_ymd_opt(1970, 1, 1).unwrap().num_days_from_ce(), 719_163);
+    /// assert_eq!(NaiveDate::from_ymd_opt(2, 1, 1).unwrap().num_days_from_ce(), 366);
+    /// assert_eq!(NaiveDate::from_ymd_opt(1, 1, 1).unwrap().num_days_from_ce(), 1);
+    /// assert_eq!(NaiveDate::from_ymd_opt(0, 1, 1).unwrap().num_days_from_ce(), -365);
+    /// ```
+    fn num_days_from_ce(&self) -> i32 {
+        // See test_num_days_from_ce_against_alternative_impl below for a more straightforward
+        // implementation.
+
+        // we know this wouldn't overflow since year is limited to 1/2^13 of i32's full range.
+        let mut year = self.year() - 1;
+        let mut ndays = 0;
+        if year < 0 {
+            let excess = 1 + (-year) / 400;
+            year += excess * 400;
+            ndays -= excess * 146_097;
+        }
+        let div_100 = year / 100;
+        ndays += ((year * 1461) >> 2) - div_100 + (div_100 >> 2);
+        ndays + self.ordinal() as i32
+    }
+}
+
+/// The common set of methods for time component.
+pub trait Timelike: Sized {
+    /// Returns the hour number from 0 to 23.
+    fn hour(&self) -> u32;
+
+    /// Returns the hour number from 1 to 12 with a boolean flag,
+    /// which is false for AM and true for PM.
+    #[inline]
+    fn hour12(&self) -> (bool, u32) {
+        let hour = self.hour();
+        let mut hour12 = hour % 12;
+        if hour12 == 0 {
+            hour12 = 12;
+        }
+        (hour >= 12, hour12)
+    }
+
+    /// Returns the minute number from 0 to 59.
+    fn minute(&self) -> u32;
+
+    /// Returns the second number from 0 to 59.
+    fn second(&self) -> u32;
+
+    /// Returns the number of nanoseconds since the whole non-leap second.
+    /// The range from 1,000,000,000 to 1,999,999,999 represents
+    /// the [leap second](./naive/struct.NaiveTime.html#leap-second-handling).
+    fn nanosecond(&self) -> u32;
+
+    /// Makes a new value with the hour number changed.
+    ///
+    /// Returns `None` when the resulting value would be invalid.
+    fn with_hour(&self, hour: u32) -> Option<Self>;
+
+    /// Makes a new value with the minute number changed.
+    ///
+    /// Returns `None` when the resulting value would be invalid.
+    fn with_minute(&self, min: u32) -> Option<Self>;
+
+    /// Makes a new value with the second number changed.
+    ///
+    /// Returns `None` when the resulting value would be invalid.
+    /// As with the [`second`](#tymethod.second) method,
+    /// the input range is restricted to 0 through 59.
+    fn with_second(&self, sec: u32) -> Option<Self>;
+
+    /// Makes a new value with nanoseconds since the whole non-leap second changed.
+    ///
+    /// Returns `None` when the resulting value would be invalid.
+    /// As with the [`nanosecond`](#tymethod.nanosecond) method,
+    /// the input range can exceed 1,000,000,000 for leap seconds.
+    fn with_nanosecond(&self, nano: u32) -> Option<Self>;
+
+    /// Returns the number of non-leap seconds past the last midnight.
+    #[inline]
+    fn num_seconds_from_midnight(&self) -> u32 {
+        self.hour() * 3600 + self.minute() * 60 + self.second()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Datelike;
+    use crate::{Duration, NaiveDate};
+
+    /// Tests `Datelike::num_days_from_ce` against an alternative implementation.
+    ///
+    /// The alternative implementation is not as short as the current one but it is simpler to
+    /// understand, with less unexplained magic constants.
+    #[test]
+    fn test_num_days_from_ce_against_alternative_impl() {
+        /// Returns the number of multiples of `div` in the range `start..end`.
+        ///
+        /// If the range `start..end` is back-to-front, i.e. `start` is greater than `end`, the
+        /// behaviour is defined by the following equation:
+        /// `in_between(start, end, div) == - in_between(end, start, div)`.
+        ///
+        /// When `div` is 1, this is equivalent to `end - start`, i.e. the length of `start..end`.
+        ///
+        /// # Panics
+        ///
+        /// Panics if `div` is not positive.
+        fn in_between(start: i32, end: i32, div: i32) -> i32 {
+            assert!(div > 0, "in_between: nonpositive div = {}", div);
+            let start = (start.div_euclid(div), start.rem_euclid(div));
+            let end = (end.div_euclid(div), end.rem_euclid(div));
+            // The lowest multiple of `div` greater than or equal to `start`, divided.
+            let start = start.0 + (start.1 != 0) as i32;
+            // The lowest multiple of `div` greater than or equal to   `end`, divided.
+            let end = end.0 + (end.1 != 0) as i32;
+            end - start
+        }
+
+        /// Alternative implementation to `Datelike::num_days_from_ce`
+        fn num_days_from_ce<Date: Datelike>(date: &Date) -> i32 {
+            let year = date.year();
+            let diff = move |div| in_between(1, year, div);
+            // 365 days a year, one more in leap years. In the gregorian calendar, leap years are all
+            // the multiples of 4 except multiples of 100 but including multiples of 400.
+            date.ordinal() as i32 + 365 * diff(1) + diff(4) - diff(100) + diff(400)
+        }
+
+        use num_iter::range_inclusive;
+
+        for year in range_inclusive(NaiveDate::MIN.year(), NaiveDate::MAX.year()) {
+            let jan1_year = NaiveDate::from_ymd_opt(year, 1, 1).unwrap();
+            assert_eq!(
+                jan1_year.num_days_from_ce(),
+                num_days_from_ce(&jan1_year),
+                "on {:?}",
+                jan1_year
+            );
+            let mid_year = jan1_year + Duration::days(133);
+            assert_eq!(
+                mid_year.num_days_from_ce(),
+                num_days_from_ce(&mid_year),
+                "on {:?}",
+                mid_year
+            );
+        }
+    }
+}

javascript-engine/external/chrono/src/weekday.rs

@@ -0,0 +1,312 @@
+use core::fmt;
+
+#[cfg(feature = "rkyv")]
+use rkyv::{Archive, Deserialize, Serialize};
+
+/// The day of week.
+///
+/// The order of the days of week depends on the context.
+/// (This is why this type does *not* implement `PartialOrd` or `Ord` traits.)
+/// One should prefer `*_from_monday` or `*_from_sunday` methods to get the correct result.
+#[derive(PartialEq, Eq, Copy, Clone, Debug, Hash)]
+#[cfg_attr(feature = "rustc-serialize", derive(RustcEncodable, RustcDecodable))]
+#[cfg_attr(feature = "rkyv", derive(Archive, Deserialize, Serialize))]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
+pub enum Weekday {
+    /// Monday.
+    Mon = 0,
+    /// Tuesday.
+    Tue = 1,
+    /// Wednesday.
+    Wed = 2,
+    /// Thursday.
+    Thu = 3,
+    /// Friday.
+    Fri = 4,
+    /// Saturday.
+    Sat = 5,
+    /// Sunday.
+    Sun = 6,
+}
+
+impl Weekday {
+    /// The next day in the week.
+    ///
+    /// `w`:        | `Mon` | `Tue` | `Wed` | `Thu` | `Fri` | `Sat` | `Sun`
+    /// ----------- | ----- | ----- | ----- | ----- | ----- | ----- | -----
+    /// `w.succ()`: | `Tue` | `Wed` | `Thu` | `Fri` | `Sat` | `Sun` | `Mon`
+    #[inline]
+    pub fn succ(&self) -> Weekday {
+        match *self {
+            Weekday::Mon => Weekday::Tue,
+            Weekday::Tue => Weekday::Wed,
+            Weekday::Wed => Weekday::Thu,
+            Weekday::Thu => Weekday::Fri,
+            Weekday::Fri => Weekday::Sat,
+            Weekday::Sat => Weekday::Sun,
+            Weekday::Sun => Weekday::Mon,
+        }
+    }
+
+    /// The previous day in the week.
+    ///
+    /// `w`:        | `Mon` | `Tue` | `Wed` | `Thu` | `Fri` | `Sat` | `Sun`
+    /// ----------- | ----- | ----- | ----- | ----- | ----- | ----- | -----
+    /// `w.pred()`: | `Sun` | `Mon` | `Tue` | `Wed` | `Thu` | `Fri` | `Sat`
+    #[inline]
+    pub fn pred(&self) -> Weekday {
+        match *self {
+            Weekday::Mon => Weekday::Sun,
+            Weekday::Tue => Weekday::Mon,
+            Weekday::Wed => Weekday::Tue,
+            Weekday::Thu => Weekday::Wed,
+            Weekday::Fri => Weekday::Thu,
+            Weekday::Sat => Weekday::Fri,
+            Weekday::Sun => Weekday::Sat,
+        }
+    }
+
+    /// Returns a day-of-week number starting from Monday = 1. (ISO 8601 weekday number)
+    ///
+    /// `w`:                      | `Mon` | `Tue` | `Wed` | `Thu` | `Fri` | `Sat` | `Sun`
+    /// ------------------------- | ----- | ----- | ----- | ----- | ----- | ----- | -----
+    /// `w.number_from_monday()`: | 1     | 2     | 3     | 4     | 5     | 6     | 7
+    #[inline]
+    pub fn number_from_monday(&self) -> u32 {
+        match *self {
+            Weekday::Mon => 1,
+            Weekday::Tue => 2,
+            Weekday::Wed => 3,
+            Weekday::Thu => 4,
+            Weekday::Fri => 5,
+            Weekday::Sat => 6,
+            Weekday::Sun => 7,
+        }
+    }
+
+    /// Returns a day-of-week number starting from Sunday = 1.
+    ///
+    /// `w`:                      | `Mon` | `Tue` | `Wed` | `Thu` | `Fri` | `Sat` | `Sun`
+    /// ------------------------- | ----- | ----- | ----- | ----- | ----- | ----- | -----
+    /// `w.number_from_sunday()`: | 2     | 3     | 4     | 5     | 6     | 7     | 1
+    #[inline]
+    pub fn number_from_sunday(&self) -> u32 {
+        match *self {
+            Weekday::Mon => 2,
+            Weekday::Tue => 3,
+            Weekday::Wed => 4,
+            Weekday::Thu => 5,
+            Weekday::Fri => 6,
+            Weekday::Sat => 7,
+            Weekday::Sun => 1,
+        }
+    }
+
+    /// Returns a day-of-week number starting from Monday = 0.
+    ///
+    /// `w`:                        | `Mon` | `Tue` | `Wed` | `Thu` | `Fri` | `Sat` | `Sun`
+    /// --------------------------- | ----- | ----- | ----- | ----- | ----- | ----- | -----
+    /// `w.num_days_from_monday()`: | 0     | 1     | 2     | 3     | 4     | 5     | 6
+    #[inline]
+    pub fn num_days_from_monday(&self) -> u32 {
+        match *self {
+            Weekday::Mon => 0,
+            Weekday::Tue => 1,
+            Weekday::Wed => 2,
+            Weekday::Thu => 3,
+            Weekday::Fri => 4,
+            Weekday::Sat => 5,
+            Weekday::Sun => 6,
+        }
+    }
+
+    /// Returns a day-of-week number starting from Sunday = 0.
+    ///
+    /// `w`:                        | `Mon` | `Tue` | `Wed` | `Thu` | `Fri` | `Sat` | `Sun`
+    /// --------------------------- | ----- | ----- | ----- | ----- | ----- | ----- | -----
+    /// `w.num_days_from_sunday()`: | 1     | 2     | 3     | 4     | 5     | 6     | 0
+    #[inline]
+    pub fn num_days_from_sunday(&self) -> u32 {
+        match *self {
+            Weekday::Mon => 1,
+            Weekday::Tue => 2,
+            Weekday::Wed => 3,
+            Weekday::Thu => 4,
+            Weekday::Fri => 5,
+            Weekday::Sat => 6,
+            Weekday::Sun => 0,
+        }
+    }
+}
+
+impl fmt::Display for Weekday {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str(match *self {
+            Weekday::Mon => "Mon",
+            Weekday::Tue => "Tue",
+            Weekday::Wed => "Wed",
+            Weekday::Thu => "Thu",
+            Weekday::Fri => "Fri",
+            Weekday::Sat => "Sat",
+            Weekday::Sun => "Sun",
+        })
+    }
+}
+
+/// Any weekday can be represented as an integer from 0 to 6, which equals to
+/// [`Weekday::num_days_from_monday`](#method.num_days_from_monday) in this implementation.
+/// Do not heavily depend on this though; use explicit methods whenever possible.
+impl num_traits::FromPrimitive for Weekday {
+    #[inline]
+    fn from_i64(n: i64) -> Option<Weekday> {
+        match n {
+            0 => Some(Weekday::Mon),
+            1 => Some(Weekday::Tue),
+            2 => Some(Weekday::Wed),
+            3 => Some(Weekday::Thu),
+            4 => Some(Weekday::Fri),
+            5 => Some(Weekday::Sat),
+            6 => Some(Weekday::Sun),
+            _ => None,
+        }
+    }
+
+    #[inline]
+    fn from_u64(n: u64) -> Option<Weekday> {
+        match n {
+            0 => Some(Weekday::Mon),
+            1 => Some(Weekday::Tue),
+            2 => Some(Weekday::Wed),
+            3 => Some(Weekday::Thu),
+            4 => Some(Weekday::Fri),
+            5 => Some(Weekday::Sat),
+            6 => Some(Weekday::Sun),
+            _ => None,
+        }
+    }
+}
+
+/// An error resulting from reading `Weekday` value with `FromStr`.
+#[derive(Clone, PartialEq, Eq)]
+pub struct ParseWeekdayError {
+    pub(crate) _dummy: (),
+}
+
+#[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+impl std::error::Error for ParseWeekdayError {}
+
+impl fmt::Display for ParseWeekdayError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_fmt(format_args!("{:?}", self))
+    }
+}
+
+impl fmt::Debug for ParseWeekdayError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "ParseWeekdayError {{ .. }}")
+    }
+}
+
+// the actual `FromStr` implementation is in the `format` module to leverage the existing code
+
+#[cfg(feature = "serde")]
+#[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
+mod weekday_serde {
+    use super::Weekday;
+    use core::fmt;
+    use serde::{de, ser};
+
+    impl ser::Serialize for Weekday {
+        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+        where
+            S: ser::Serializer,
+        {
+            serializer.collect_str(&self)
+        }
+    }
+
+    struct WeekdayVisitor;
+
+    impl<'de> de::Visitor<'de> for WeekdayVisitor {
+        type Value = Weekday;
+
+        fn expecting(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            f.write_str("Weekday")
+        }
+
+        fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
+        where
+            E: de::Error,
+        {
+            value.parse().map_err(|_| E::custom("short or long weekday names expected"))
+        }
+    }
+
+    impl<'de> de::Deserialize<'de> for Weekday {
+        fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+        where
+            D: de::Deserializer<'de>,
+        {
+            deserializer.deserialize_str(WeekdayVisitor)
+        }
+    }
+
+    #[test]
+    fn test_serde_serialize() {
+        use serde_json::to_string;
+        use Weekday::*;
+
+        let cases: Vec<(Weekday, &str)> = vec![
+            (Mon, "\"Mon\""),
+            (Tue, "\"Tue\""),
+            (Wed, "\"Wed\""),
+            (Thu, "\"Thu\""),
+            (Fri, "\"Fri\""),
+            (Sat, "\"Sat\""),
+            (Sun, "\"Sun\""),
+        ];
+
+        for (weekday, expected_str) in cases {
+            let string = to_string(&weekday).unwrap();
+            assert_eq!(string, expected_str);
+        }
+    }
+
+    #[test]
+    fn test_serde_deserialize() {
+        use serde_json::from_str;
+        use Weekday::*;
+
+        let cases: Vec<(&str, Weekday)> = vec![
+            ("\"mon\"", Mon),
+            ("\"MONDAY\"", Mon),
+            ("\"MonDay\"", Mon),
+            ("\"mOn\"", Mon),
+            ("\"tue\"", Tue),
+            ("\"tuesday\"", Tue),
+            ("\"wed\"", Wed),
+            ("\"wednesday\"", Wed),
+            ("\"thu\"", Thu),
+            ("\"thursday\"", Thu),
+            ("\"fri\"", Fri),
+            ("\"friday\"", Fri),
+            ("\"sat\"", Sat),
+            ("\"saturday\"", Sat),
+            ("\"sun\"", Sun),
+            ("\"sunday\"", Sun),
+        ];
+
+        for (str, expected_weekday) in cases {
+            let weekday = from_str::<Weekday>(str).unwrap();
+            assert_eq!(weekday, expected_weekday);
+        }
+
+        let errors: Vec<&str> =
+            vec!["\"not a weekday\"", "\"monDAYs\"", "\"mond\"", "mon", "\"thur\"", "\"thurs\""];
+
+        for str in errors {
+            from_str::<Weekday>(str).unwrap_err();
+        }
+    }
+}