ChangeLog for Chrono
====================
This documents all notable changes to [Chrono](https://github.com/chronotope/chrono).
Chrono obeys the principle of [Semantic Versioning](http://semver.org/).
There were/are numerous minor versions before 1.0 due to the language changes.
Versions with only mechnical changes will be omitted from the following list.
## 0.3.1 (2017-05-02)
### Added
- `Weekday` now implements `FromStr`, `Serialize` and `Deserialize`. (#113)
The syntax is identical to `%A`, i.e. either the shortest or the longest form of English names.
### Changed
- Serde 1.0 is now supported. (#142)
This is technically a breaking change because Serde 0.9 and 1.0 are not compatible,
but this time we decided not to issue a minor version because
we have already seen Serde 0.8 and 0.9 compatibility problems even after 0.3.0 and
a new minor version turned out to be not very helpful for this kind of issues.
### Fixed
- Fixed a bug that the leap second can be mapped wrongly in the local time zone.
Only occurs when the local time zone is behind UTC. (#130)
## 0.3.0 (2017-02-07)
The project has moved to the [Chronotope](https://github.com/chronotope/) organization.
### Added
- `chrono::prelude` module has been added. All other glob imports are now discouraged.
- `FixedOffset` can be added to or subtracted from any timelike types.
- `FixedOffset::local_minus_utc` and `FixedOffset::utc_minus_local` methods have been added.
Note that the old `Offset::local_minus_utc` method is gone; see below.
- Serde support for non-self-describing formats like Bincode is added. (#89)
- Added `Item::Owned{Literal,Space}` variants for owned formatting items. (#76)
- Formatting items and the `Parsed` type have been slightly adjusted so that
they can be internally extended without breaking any compatibility.
- `Weekday` is now `Hash`able. (#109)
- `ParseError` now implements `Eq` as well as `PartialEq`. (#114)
- More documentation improvements. (#101, #108, #112)
### Changed
- Chrono now only supports Rust 1.13.0 or later (previously: Rust 1.8.0 or later).
- Serde 0.9 is now supported.
Due to the API difference, support for 0.8 or older is discontinued. (#122)
- Rustc-serialize implementations are now on par with corresponding Serde implementations.
They both standardize on the `std::fmt::Debug` textual output.
**This is a silent breaking change (hopefully the last though).**
You should be prepared for the format change if you depended on rustc-serialize.
- `Offset::local_minus_utc` is now `Offset::fix`, and returns `FixedOffset` instead of a duration.
This makes every time zone operation operate within a bias less than one day,
and vastly simplifies many logics.
- `chrono::format::format` now receives `FixedOffset` instead of `time::Duration`.
- The following methods and implementations have been renamed and older names have been *removed*.
The older names will be reused for the same methods with `std::time::Duration` in the future.
- `checked_*` → `checked_*_signed` in `Date`, `DateTime`, `NaiveDate` and `NaiveDateTime` types
- `overflowing_*` → `overflowing_*_signed` in the `NaiveTime` type
- All subtraction implementations between two time instants have been moved to
`signed_duration_since`, following the naming in `std::time`.
### Fixed
- Fixed a panic when the `Local` offset receives a leap second. (#123)
### Removed
- Rustc-serialize support for `Date<Tz>` types and all offset types has been dropped.
These implementations were automatically derived and never had been in a good shape.
Moreover there are no corresponding Serde implementations, limiting their usefulness.
In the future they may be revived with more complete implementations.
- The following method aliases deprecated in the 0.2 branch have been removed.
- `DateTime::num_seconds_from_unix_epoch` (→ `DateTime::timestamp`)
- `NaiveDateTime::from_num_seconds_from_unix_epoch` (→ `NaiveDateTime::from_timestamp`)
- `NaiveDateTime::from_num_seconds_from_unix_epoch_opt` (→ `NaiveDateTime::from_timestamp_opt`)
- `NaiveDateTime::num_seconds_unix_epoch` (→ `NaiveDateTime::timestamp`)
- Formatting items are no longer `Copy`, except for `chrono::format::Pad`.
- `chrono::offset::add_with_leapsecond` has been removed.
Use a direct addition with `FixedOffset` instead.
## 0.2.25 (2016-08-04)
This is the last version officially supports Rust 1.12.0 or older.
(0.2.24 was accidentally uploaded without a proper check for warnings in the default state,
and replaced by 0.2.25 very shortly. Duh.)
### Added
- Serde 0.8 is now supported. 0.7 also remains supported. (#86)
### Fixed
- The deserialization implementation for rustc-serialize now properly verifies the input.
All serialization codes are also now thoroughly tested. (#42)
## 0.2.23 (2016-08-03)
### Added
- The documentation was greatly improved for several types,
and tons of cross-references have been added. (#77, #78, #80, #82)
- `DateTime::timestamp_subsec_{millis,micros,nanos}` methods have been added. (#81)
### Fixed
- When the system time records a leap second,
the nanosecond component was mistakenly reset to zero. (#84)
- `Local` offset misbehaves in Windows for August and later,
due to the long-standing libtime bug (dates back to mid-2015).
Workaround has been implemented. (#85)
## 0.2.22 (2016-04-22)
### Fixed
- `%.6f` and `%.9f` used to print only three digits when the nanosecond part is zero. (#71)
- The documentation for `%+` has been updated to reflect the current status. (#71)
## 0.2.21 (2016-03-29)
### Fixed
- `Fixed::LongWeekdayName` was unable to recognize `"sunday"` (whoops). (#66)
## 0.2.20 (2016-03-06)
### Changed
- `serde` dependency has been updated to 0.7. (#63, #64)
## 0.2.19 (2016-02-05)
### Added
- The documentation for `Date` is made clear about its ambiguity and guarantees.
### Fixed
- `DateTime::date` had been wrong when the local date and the UTC date is in disagreement. (#61)
## 0.2.18 (2016-01-23)
### Fixed
- Chrono no longer pulls a superfluous `rand` dependency. (#57)
## 0.2.17 (2015-11-22)
### Added
- Naive date and time types and `DateTime` now have a `serde` support.
They serialize as an ISO 8601 / RFC 3339 string just like `Debug`. (#51)
## 0.2.16 (2015-09-06)
### Added
- Added `%.3f`, `%.6f` and `%.9f` specifier for formatting fractional seconds
up to 3, 6 or 9 decimal digits. This is a natural extension to the existing `%f`.
Note that this is (not yet) generic, no other value of precision is supported. (#45)
### Changed
- Forbade unsized types from implementing `Datelike` and `Timelike`.
This does not make a big harm as any type implementing them should be already sized
to be practical, but this change still can break highly generic codes. (#46)
### Fixed
- Fixed a broken link in the `README.md`. (#41)
## 0.2.15 (2015-07-05)
### Added
- Padding modifiers `%_?`, `%-?` and `%0?` are implemented.
They are glibc extensions which seem to be reasonably widespread (e.g. Ruby).
- Added `%:z` specifier and corresponding formatting items
which is essentially same to `%z` but with a colon.
- Added a new specifier `%.f` which precision adapts from the input.
This was added as a response to the UX problems in the original nanosecond specifier `%f`.
### Fixed
- `Numeric::Timestamp` specifier (`%s`) was ignoring the time zone offset when provided.
- Improved the documentation and associated tests for `strftime`.
## 0.2.14 (2015-05-15)
### Fixed
- `NaiveDateTime +/- Duration` or `NaiveTime +/- Duration` could have gone wrong
when the `Duration` to be added is negative and has a fractional second part.
This was caused by an underflow in the conversion from `Duration` to the parts;
the lack of tests for this case allowed a bug. (#37)
## 0.2.13 (2015-04-29)
### Added
- The optional dependency on `rustc_serialize` and
relevant `Rustc{En,De}codable` implementations for supported types has been added.
This is enabled by the `rustc-serialize` Cargo feature. (#34)
### Changed
- `chrono::Duration` reexport is changed to that of crates.io `time` crate.
This enables Rust 1.0 beta compatibility.
## 0.2.4 (2015-03-03)
### Fixed
- Clarified the meaning of `Date<Tz>` and fixed unwanted conversion problem
that only occurs with positive UTC offsets. (#27)
## 0.2.3 (2015-02-27)
### Added
- `DateTime<Tz>` and `Date<Tz>` is now `Copy`/`Send` when `Tz::Offset` is `Copy`/`Send`.
The implementations for them were mistakenly omitted. (#25)
### Fixed
- `Local::from_utc_datetime` didn't set a correct offset. (#26)
## 0.2.1 (2015-02-21)
### Changed
- `DelayedFormat` no longer conveys a redundant lifetime.
## 0.2.0 (2015-02-19)
### Added
- `Offset` is splitted into `TimeZone` (constructor) and `Offset` (storage) types.
You would normally see only the former, as the latter is mostly an implementation detail.
Most importantly, `Local` now can be used to directly construct timezone-aware values.
Some types (currently, `UTC` and `FixedOffset`) are both `TimeZone` and `Offset`,
but others aren't (e.g. `Local` is not what is being stored to each `DateTime` values).
- `LocalResult::map` convenience method has been added.
- `TimeZone` now allows a construction of `DateTime` values from UNIX timestamp,
via `timestamp` and `timestamp_opt` methods.
- `TimeZone` now also has a method for parsing `DateTime`, namely `datetime_from_str`.
- The following methods have been added to all date and time types:
- `checked_add`
- `checked_sub`
- `format_with_items`
- The following methods have been added to all timezone-aware types:
- `timezone`
- `with_timezone`
- `naive_utc`
- `naive_local`
- `parse_from_str` method has been added to all naive types and `DateTime<FixedOffset>`.
- All naive types and instances of `DateTime` with time zones `UTC`, `Local` and `FixedOffset`
implement the `FromStr` trait. They parse what `std::fmt::Debug` would print.
- `chrono::format` has been greatly rewritten.
- The formatting syntax parser is modular now, available at `chrono::format::strftime`.
- The parser and resolution algorithm is also modular, the former is available at
`chrono::format::parse` while the latter is available at `chrono::format::parsed`.
- Explicit support for RFC 2822 and 3339 syntaxes is landed.
- There is a minor formatting difference with atypical values,
e.g. for years not between 1 BCE and 9999 CE.
### Changed
- Most uses of `Offset` are converted to `TimeZone`.
In fact, *all* user-facing code is expected to be `Offset`-free.
- `[Naive]DateTime::*num_seconds_from_unix_epoch*` methods have been renamed to
simply `timestamp` or `from_timestamp*`. The original names have been deprecated.
### Removed
- `Time` has been removed. This also prompts a related set of methods in `TimeZone`.
This is in principle possible, but in practice has seen a little use
because it can only be meaningfully constructed via an existing `DateTime` value.
This made many operations to `Time` unintuitive or ambiguous,
so we simply let it go.
In the case that `Time` is really required, one can use a simpler `NaiveTime`.
`NaiveTime` and `NaiveDate` can be freely combined and splitted,
and `TimeZone::from_{local,utc}_datetime` can be used to convert from/to the local time.
- `with_offset` method has been removed. Use `with_timezone` method instead.
(This is not deprecated since it is an integral part of offset reform.)
## 0.1.14 (2015-01-10)
### Added
- Added a missing `std::fmt::String` impl for `Local`.
## 0.1.13 (2015-01-10)
### Changed
- Most types now implement both `std::fmt::Show` and `std::fmt::String`,
with the former used for the stricter output and the latter used for more casual output.
### Removed
- `Offset::name` has been replaced by a `std::fmt::String` implementation to `Offset`.
## 0.1.12 (2015-01-08)
### Removed
- `Duration + T` no longer works due to the updated impl reachability rules.
Use `T + Duration` as a workaround.
## 0.1.4 (2014-12-13)
### Fixed
- Fixed a bug that `Date::and_*` methods with an offset that can change the date are
off by one day.
## 0.1.3 (2014-11-28)
### Added
- `{Date,Time,DateTime}::with_offset` methods have been added.
- `LocalResult` now implements a common set of traits.
- `LocalResult::and_*` methods have been added.
They are useful for safely chaining `LocalResult<Date<Off>>` methods
to make `LocalResult<DateTime<Off>>`.
### Changed
- `Offset::name` now returns `SendStr`.
- `{Date,Time} - Duration` overloadings are now allowed.
## 0.1.2 (2014-11-24)
### Added
- `Duration + Date` overloading is now allowed.
### Changed
- Chrono no longer needs `num` dependency.
## 0.1.0 (2014-11-20)
The initial version that was available to `crates.io`.