Crate icu_calendar

Types for dealing with dates and custom calendars.

This module is published as its own crate (icu_calendar) and as part of the icu crate. See the latter for more details on the ICU4X project. The types module has a lot of common types for dealing with dates.

Calendar is a trait that allows one to define custom calendars, and Date can represent dates for arbitrary calendars.

The Iso and Gregorian types are implementations for the ISO and Gregorian calendars respectively. Further calendars can be found in the cal module.

Most interaction with this crate will be done via the Date type.

Some of the algorithms implemented here are based on Dershowitz, Nachum, and Edward M. Reingold. Calendrical calculations. Cambridge University Press, 2008. with associated Lisp code found at https://github.com/EdReingold/calendar-code2.

Examples

Examples of date manipulation using Date object. Date objects are useful for working with dates, encompassing information about the day, month, year, as well as the calendar type.

use icu::calendar::{types::Weekday, Date};

// Creating ISO date: 1992-09-02.
let mut date_iso = Date::try_new_iso(1992, 9, 2)
    .expect("Failed to initialize ISO Date instance.");

assert_eq!(date_iso.day_of_week(), Weekday::Wednesday);
assert_eq!(date_iso.era_year().year, 1992);
assert_eq!(date_iso.month().ordinal, 9);
assert_eq!(date_iso.day_of_month().0, 2);

// Answering questions about days in month and year.
assert_eq!(date_iso.days_in_year(), 366);
assert_eq!(date_iso.days_in_month(), 30);

Example of converting an ISO date across Indian and Buddhist calendars.

use icu::calendar::cal::{Buddhist, Indian};
use icu::calendar::Date;

// Creating ISO date: 1992-09-02.
let mut date_iso = Date::try_new_iso(1992, 9, 2)
    .expect("Failed to initialize ISO Date instance.");

assert_eq!(date_iso.era_year().year, 1992);
assert_eq!(date_iso.month().ordinal, 9);
assert_eq!(date_iso.day_of_month().0, 2);

// Conversion into Indian calendar: 1914-08-02.
let date_indian = date_iso.to_calendar(Indian);
assert_eq!(date_indian.era_year().year, 1914);
assert_eq!(date_indian.month().ordinal, 6);
assert_eq!(date_indian.day_of_month().0, 11);

// Conversion into Buddhist calendar: 2535-09-02.
let date_buddhist = date_iso.to_calendar(Buddhist);
assert_eq!(date_buddhist.era_year().year, 2535);
assert_eq!(date_buddhist.month().ordinal, 9);
assert_eq!(date_buddhist.day_of_month().0, 2);

Re-exports

pub use cal::AnyCalendar;

pub use cal::AnyCalendarKind;

pub use cal::Gregorian;

pub use cal::Iso;

Modules

cal

Types for individual calendars

preferences

Locale preferences used by this crate

provider

🚧 [Unstable] Data provider struct definitions for this ICU4X component.

types

This module contains various types used by icu_calendar and icu::datetime

week

Functions for region-specific weekday information.

Structs

Date

A date for a given calendar.

RangeError

An argument is out of range for its domain.

Ref

This exists as a wrapper around &'a T so that Date<&'a C> is possible for calendar C.

Enums

DateError

Error type for date creation.

ParseError

An error returned from parsing an RFC 9557 string to an icu_calendar type.

Traits

AsCalendar

Types that contain a calendar

Calendar

A calendar implementation

IntoAnyCalendar

Trait for calendars that may be converted to AnyCalendar