Date and time library for Rust
This release fixes a panic introduced in chrono 0.4.27 in FromStr<DateTime<Utc>>
(#1253).
Chrono now has a Discord channel.
parse_rfc3339_relaxed
(#1254)TimeZone::datetime_from_str
(#1251)FromStr
for Weekday
and Month
(#1226, thanks @wfraser)i686
and wasm32-wasi
(#1237)Thanks to all contributors on behalf of the chrono team, @djc and @pitdicker!
The initial version that was available to crates.io
. Description from README of chrono 0.1.3:
Date and time handling for Rust. It aims to be a feature-complete superset of the time library. In particular,
There were several previous attempts to bring a good date and time library to Rust, which Chrono builts upon and should acknowledge:
Chrono used to have a Duration
type, which represents the time span. Now Rust standard library includes it as std::time::duration::Duration
and Chrono simply reexports it.
Chrono provides a DateTime
type for the combined date and time.
DateTime
, among others, is timezone-aware and must be constructed from the timezone object (Offset
). DateTime
s with different offsets do not mix, but can be converted to each other.
You can get the current date and time in the UTC timezone (UTC::now()
) or in the local timezone (Local::now()
).
use chrono::{UTC, Local, DateTime};
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.
use chrono::{UTC, Offset, Weekday, LocalResult};
let dt = UTC.ymd(2014, 7, 8).and_hms(9, 10, 11); // `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(9, 10, 11));
// July 8 is Tuesday in ISO week 28 of the year 2014.
assert_eq!(dt, UTC.isoywd(2014, 28, Weekday::Tue).and_hms(9, 10, 11));
let dt = UTC.ymd(2014, 7, 8).and_hms_milli(9, 10, 11, 12); // `2014-07-08T09:10:11.012Z`
assert_eq!(dt, UTC.ymd(2014, 7, 8).and_hms_micro(9, 10, 11, 12_000));
assert_eq!(dt, UTC.ymd(2014, 7, 8).and_hms_nano(9, 10, 11, 12_000_000));
// dynamic verification
assert_eq!(UTC.ymd_opt(2014, 7, 8).and_hms_opt(21, 15, 33),
LocalResult::Single(UTC.ymd(2014, 7, 8).and_hms(21, 15, 33)));
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);
Various properties are available to the date and time, and can be altered individually. Most of them are defined in the traits Datelike
and Timelike
which you should use
before. Addition and subtraction is also supported. The following illustrates most supported operations to the date and time:
# /* we intentionally fake the datetime...
use chrono::{UTC, Local, Datelike, Timelike, Weekday, Duration};
// assume this returned `2014-11-28T21:45:59.324310806+09:00`:
let dt = Local::now();
# */ // up to here. we now define a fixed datetime for the illustrative purpose.
# use chrono::{UTC, FixedOffset, Offset, Datelike, Timelike, Weekday, Duration};
# let dt = FixedOffset::east(9*3600).ymd(2014, 11, 28).and_hms_nano(21, 45, 59, 324310806);
// 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, ..., Sat=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
// offset accessor and manipulation
assert_eq!(dt.offset().local_minus_utc(), Duration::hours(9));
assert_eq!(dt.with_offset(UTC), UTC.ymd(2014, 11, 28).and_hms_nano(12, 45, 59, 324310806));
// 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
assert_eq!(UTC.ymd(2014, 11, 14).and_hms(8, 9, 10) - UTC.ymd(2014, 11, 14).and_hms(10, 9, 8),
Duration::seconds(-2 * 3600 + 2));
assert_eq!(UTC.ymd(1970, 1, 1).and_hms(0, 0, 0) + Duration::seconds(1_000_000_000),
UTC.ymd(2001, 9, 9).and_hms(1, 46, 40));
assert_eq!(UTC.ymd(1970, 1, 1).and_hms(0, 0, 0) - Duration::seconds(1_000_000_000),
UTC.ymd(1938, 4, 24).and_hms(22, 13, 20));
Formatting is done via the format
method, which format is equivalent to the familiar strftime
format. The default to_string
method also gives a reasonable representation.
use chrono::{UTC, Offset};
let dt = UTC.ymd(2014, 11, 28).and_hms(12, 0, 9);
assert_eq!(dt.format("%Y-%m-%d %H:%M:%S").to_string(), "2014-11-28 12:00:09".into_string());
assert_eq!(dt.format("%a %b %e %T %Y").to_string(), "Fri Nov 28 12:00:09 2014".into_string());
assert_eq!(dt.format("%a %b %e %T %Y").to_string(), dt.format("%c").to_string());
assert_eq!(dt.to_string(), "2014-11-28T12:00:09Z".into_string());
Chrono also provides an individual date type (Date
) and time type (Time
). They also have offsets attached, and have to be constructed via offsets. Most operations available to DateTime
are also available to Date
and Time
whenever appropriate.
use chrono::{UTC, Local, Offset, LocalResult, Datelike, Weekday};
# // 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(2014, 11, 28).weekday(), Weekday::Fri);
assert_eq!(UTC.ymd_opt(2014, 11, 31), LocalResult::None);
assert_eq!(UTC.hms_milli(7, 8, 9, 10).format("%H%M%S").to_string(), "070809".into_string());
DateTime
has two methods, date
and time
, which return narrow views to its date and time components respectively.
Chrono provides naive counterparts to Date
, Time
and DateTime
as NaiveDate
, NaiveTime
and NaiveDateTime
respectively.
They have almost equivalent interfaces as their timezone-aware twins, but are not associated to offsets obviously and can be quite low-level. They are mostly useful for building blocks for higher-level types.
Language changes, updated documentations.
std::fmt::WriteError
is now std::fmt::Error
.{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>>
.
Offset::name
now returns SendStr
.
{Date,Time} - Duration
overloadings are now allowed.
Language changes.
Copy
is now opt-in. Every Copy
able type is made to implement Copy
. While unlikely, I haven't deeply thought about Copy
ability so it might change in 0.2.Date::and_*
methods with an offset that can change the date are
off by one day.Language changes.
Add
and Sub
requires a value instead of a reference.Fixed tests per language changes and .travis.yml
.
This also switches to the crates.io dependency unconditionally.
Language changes.
Eq
no longer accepts the reflexive type parameter.
(this doesn't change the actual interface, as Eq
is simply a marker for total ordering. PartialEq
retains it.)Language changes.
#[deriving]
is now #[derive]
.[T, ..n]
is no longer valid.#[derive(Hash)]
failing out.IoError
.