ZonedDateTime

A ZonedDateTime represents a date and time in a specific time zone and calendar system.

install	`yarn add @internationalized/date`
version	3.0.0-rc.0
usage	`import {ZonedDateTime} from '@internationalized/date'`

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Introduction#

A ZonedDateTime object represents an exact date and time in a specific time zone, in a specific calendar system such as the Gregorian calendar. Use this type to represent an exact moment in time at a particular location on Earth.

A ZonedDateTime can be created using the constructor. This example creates a date that represents February 3rd, 2022 at 9:15 AM in the Gregorian calendar system, with a time zone of "America/Los Angeles".

import {ZonedDateTime} from '@internationalized/date';

let date = new ZonedDateTime(
  // Date
  2022, 2, 3,
  // Time zone and UTC offset
  'America/Los_Angeles', -28800000,
  // Time
  12, 24, 45
);

import {ZonedDateTime} from '@internationalized/date';

let date = new ZonedDateTime(
  // Date
  2022, 2, 3,
  // Time zone and UTC offset
  'America/Los_Angeles', -28800000,
  // Time
  12, 24, 45
);

import {ZonedDateTime} from '@internationalized/date';

let date =
  new ZonedDateTime(
    // Date
    2022,
    2,
    3,
    // Time zone and UTC offset
    'America/Los_Angeles',
    -28800000,
    // Time
    12,
    24,
    45
  );

You can also create a ZonedDateTime by parsing an ISO 8601 formatted string using the one of the following functions:

parseZonedDateTime – This function parses a date with an explicit time zone and optional UTC offset attached (e.g. "2021-11-07T00:45[America/Los_Angeles]" or "2021-11-07T00:45-07:00[America/Los_Angeles]"). This format preserves the maximum amount of information. If the exact local time and time zone that a user selected is important, use this format. Storing the time zone and offset that was selected rather than converting to UTC ensures that the local time is correct regardless of daylight saving rule changes (e.g. if a locale abolishes DST). Examples where this applies include calendar events, reminders, and other times that occur in a particular location.
parseAbsolute – This function parses an absolute date and time that occurs at the same instant at all locations on Earth. It can be represented in UTC (e.g. "2021-11-07T07:45:00Z"), or stored with a particular offset (e.g. "2021-11-07T07:45:00-07:00"). A time zone identifier, e.g. America/Los_Angeles, must be passed, and the result will be converted into that time zone. Absolute times are the best way to represent events that occurred in the past, or future events where an exact time is needed, regardless of time zone.
parseAbsoluteToLocal – This function parses an absolute date and time into the current user's local time zone. It is a shortcut for parseAbsolute, and accepts the same formats.

import {parseZonedDateTime} from '@internationalized/date';

let date = parseZonedDateTime('2022-11-07T00:45[America/Los_Angeles]');
let date = parseAbsolute('2021-11-07T07:45:00Z', 'America/Los_Angeles');
let date = parseAbsoluteToLocal('2021-11-07T07:45:00Z');

import {parseZonedDateTime} from '@internationalized/date';

let date = parseZonedDateTime(
  '2022-11-07T00:45[America/Los_Angeles]'
);
let date = parseAbsolute(
  '2021-11-07T07:45:00Z',
  'America/Los_Angeles'
);
let date = parseAbsoluteToLocal('2021-11-07T07:45:00Z');

import {parseZonedDateTime} from '@internationalized/date';

let date =
  parseZonedDateTime(
    '2022-11-07T00:45[America/Los_Angeles]'
  );
let date = parseAbsolute(
  '2021-11-07T07:45:00Z',
  'America/Los_Angeles'
);
let date =
  parseAbsoluteToLocal(
    '2021-11-07T07:45:00Z'
  );

Once you have a ZonedDateTime object, you can read its properties, or manipulate it as described in the Manipulating dates section below. You can also convert it to an ISO 8601 string, native JavaScript Date object, or another representation. See the Conversion section below for details.

let date = new ZonedDateTime(
  2022, 2, 3,
  'America/Los_Angeles', -28800000,
  12, 24, 45
);

date.toString(); // '2022-02-03T12:24:45-08:00[America/Los_Angeles]'

let date = new ZonedDateTime(
  2022,
  2,
  3,
  'America/Los_Angeles',
  -28800000,
  12,
  24,
  45
);

date.toString(); // '2022-02-03T12:24:45-08:00[America/Los_Angeles]'

let date =
  new ZonedDateTime(
    2022,
    2,
    3,
    'America/Los_Angeles',
    -28800000,
    12,
    24,
    45
  );

date.toString(); // '2022-02-03T12:24:45-08:00[America/Los_Angeles]'

Interface#

Properties

Name	Type	Description
`calendar`	`Calendar`	The calendar system associated with this date, e.g. Gregorian.
`era`	`string`	The calendar era for this date, e.g. "BC" or "AD".
`year`	`number`	The year of this date within the era.
`month`	`number`	The month number within the year. Note that some calendar systems such as Hebrew may have a variable number of months per year. Therefore, month numbers may not always correspond to the same month names in different years.
`day`	`number`	The day number within the month.
`hour`	`number`	The hour in the day, numbered from 0 to 23.
`minute`	`number`	The minute in the hour.
`second`	`number`	The second in the minute.
`millisecond`	`number`	The millisecond in the second.
`timeZone`	`string`	The IANA time zone identifier that this date and time is represented in.
`offset`	`number`	The UTC offset for this time, in seconds.

Methods

Method	Description
`constructor( (...args: any[] )): void`
`copy(): ZonedDateTime`	Returns a copy of this date.
`add( (duration: DateTimeDuration )): void`	Returns a new `ZonedDateTime` with the given duration added to it.
`subtract( (duration: DateTimeDuration )): void`	Returns a new `ZonedDateTime` with the given duration subtracted from it.
`set( (fields: DateFields & & TimeFields, , disambiguation?: Disambiguation )): void`	Returns a new `ZonedDateTime` with the given fields set to the provided values. Other fields will be constrained accordingly.
`cycle( field: DateField \| \| TimeField, amount: number, options?: CycleTimeOptions ): void`	Returns a new `ZonedDateTime` with the given field adjusted by a specified amount. When the resulting value reaches the limits of the field, it wraps around.
`toDate(): void`	Converts the date to a native JavaScript Date object.
`toString(): void`	Converts the date to an ISO 8601 formatted string, including the UTC offset and time zone identifier.
`toAbsoluteString(): void`	Converts the date to an ISO 8601 formatted string in UTC.
`compare( (b: CalendarDate \| CalendarDateTime \| ZonedDateTime )): void`	Compares this date with another. A negative result indicates that this date is before the given one, and a positive date indicates that it is after.

Calendar systems#

By default, ZonedDateTime uses the Gregorian calendar system, but many other calendar systems that are used around the world are supported, such as Hebrew, Indian, Islamic, Buddhist, Ethiopic, and more. A Calendar instance can be passed to the ZonedDateTime constructor to represent dates in that calendar system.

This example creates a date in the Buddhist calendar system, which is equivalent to April 4th, 2020 at 9:15 AM in the Gregorian calendar.

import {BuddhistCalendar} from '@internationalized/date';

let date = new ZonedDateTime(
  new BuddhistCalendar(), 2563, 4, 30,
  'America/Los_Angeles', -28800000,
  9, 15
);

import {BuddhistCalendar} from '@internationalized/date';

let date = new ZonedDateTime(
  new BuddhistCalendar(), 2563, 4, 30,
  'America/Los_Angeles', -28800000,
  9, 15
);

import {BuddhistCalendar} from '@internationalized/date';

let date =
  new ZonedDateTime(
    new BuddhistCalendar(),
    2563,
    4,
    30,
    'America/Los_Angeles',
    -28800000,
    9,
    15
  );

See the Calendar docs for details about the supported calendars.

Eras#

Many calendar systems have only one era, or a modern era and a pre-modern era (e.g. AD and BC in the Gregorian calendar). However, other calendar systems may have many eras. For example, the Japanese calendar has eras for the reign of each Emperor. ZonedDateTime represents eras using string identifiers, which can be passed as an additional parameter to the constructor before the year. When eras are present, years are numbered starting from 1 within the era.

This example creates a date in the Japanese calendar system, which is equivalent to April 4th, 2020 at 9:15 AM in the Gregorian calendar.

import {JapaneseCalendar} from '@internationalized/date';

let date = new ZonedDateTime(
  new JapaneseCalendar(), 'heisei', 31, 4, 30,
  'America/Los_Angeles', -28800000,
  9, 15
);

import {JapaneseCalendar} from '@internationalized/date';

let date = new ZonedDateTime(
  new JapaneseCalendar(), 'heisei', 31, 4, 30,
  'America/Los_Angeles', -28800000,
  9, 15
);

import {JapaneseCalendar} from '@internationalized/date';

let date =
  new ZonedDateTime(
    new JapaneseCalendar(),
    'heisei',
    31,
    4,
    30,
    'America/Los_Angeles',
    -28800000,
    9,
    15
  );

A list of valid era identifiers can be retrieved using the getEras method of a Calendar instance. If an era is not provided, the date is assumed to be in the current era.

Converting between calendars#

The toCalendar function can be used to convert a date from one calendar system to another.

This example converts a Gregorian date to a Hebrew one.

import {toCalendar, HebrewCalendar} from '@internationalized/date';

let gregorianDate = new ZonedDateTime(
  2020, 9, 19,
  'America/Los_Angeles', -28800000,
  10, 30
);

let hebrewDate = toCalendar(gregorianDate, new HebrewCalendar());

import {
  HebrewCalendar,
  toCalendar
} from '@internationalized/date';

let gregorianDate = new ZonedDateTime(
  2020,
  9,
  19,
  'America/Los_Angeles',
  -28800000,
  10,
  30
);

let hebrewDate = toCalendar(
  gregorianDate,
  new HebrewCalendar()
);

import {
  HebrewCalendar,
  toCalendar
} from '@internationalized/date';

let gregorianDate =
  new ZonedDateTime(
    2020,
    9,
    19,
    'America/Los_Angeles',
    -28800000,
    10,
    30
  );

let hebrewDate =
  toCalendar(
    gregorianDate,
    new HebrewCalendar()
  );

Manipulating dates#

Adding and subtracting durations#

A DateTimeDuration is an object that represents an amount of time, with fields such as years, months, hours, and minutes. The add and subtract methods of ZonedDateTime objects can be used to adjust the date by the given duration. These methods return a new date, and do not mutate the original.

let date = parseZonedDateTime('2022-02-03T09:45[America/Los_Angeles]');

date.add({ weeks: 1 }); // 2022-02-10T09:45[America/Los_Angeles]
date.add({ months: 1 }); // 2022-03-03T09:45[America/Los_Angeles]
date.add({ years: 1, months: 1, days: 1 }); // 2023-03-04T09:45[America/Los_Angeles]
date.add({ hours: 1 }); // 2022-02-03T10:45[America/Los_Angeles]
date.add({ minutes: 30 }); // 2022-02-03T10:15[America/Los_Angeles]

date.subtract({ weeks: 1 }); // 2022-01-27T09:45[America/Los_Angeles]
date.subtract({ months: 1 }); // 2022-01-03T09:45[America/Los_Angeles]
date.subtract({ years: 1, months: 1, days: 1 }); // 2021-01-02T09:45[America/Los_Angeles]
date.subtract({ hours: 1 }); // 2022-02-03T8:45[America/Los_Angeles]
date.subtract({ minutes: 30 }); // 2022-02-03T09:15[America/Los_Angeles]

let date = parseZonedDateTime(
  '2022-02-03T09:45[America/Los_Angeles]'
);

date.add({ weeks: 1 }); // 2022-02-10T09:45[America/Los_Angeles]
date.add({ months: 1 }); // 2022-03-03T09:45[America/Los_Angeles]
date.add({ years: 1, months: 1, days: 1 }); // 2023-03-04T09:45[America/Los_Angeles]
date.add({ hours: 1 }); // 2022-02-03T10:45[America/Los_Angeles]
date.add({ minutes: 30 }); // 2022-02-03T10:15[America/Los_Angeles]

date.subtract({ weeks: 1 }); // 2022-01-27T09:45[America/Los_Angeles]
date.subtract({ months: 1 }); // 2022-01-03T09:45[America/Los_Angeles]
date.subtract({ years: 1, months: 1, days: 1 }); // 2021-01-02T09:45[America/Los_Angeles]
date.subtract({ hours: 1 }); // 2022-02-03T8:45[America/Los_Angeles]
date.subtract({ minutes: 30 }); // 2022-02-03T09:15[America/Los_Angeles]

let date =
  parseZonedDateTime(
    '2022-02-03T09:45[America/Los_Angeles]'
  );

date.add({ weeks: 1 }); // 2022-02-10T09:45[America/Los_Angeles]
date.add({ months: 1 }); // 2022-03-03T09:45[America/Los_Angeles]
date.add({
  years: 1,
  months: 1,
  days: 1
}); // 2023-03-04T09:45[America/Los_Angeles]
date.add({ hours: 1 }); // 2022-02-03T10:45[America/Los_Angeles]
date.add({
  minutes: 30
}); // 2022-02-03T10:15[America/Los_Angeles]

date.subtract({
  weeks: 1
}); // 2022-01-27T09:45[America/Los_Angeles]
date.subtract({
  months: 1
}); // 2022-01-03T09:45[America/Los_Angeles]
date.subtract({
  years: 1,
  months: 1,
  days: 1
}); // 2021-01-02T09:45[America/Los_Angeles]
date.subtract({
  hours: 1
}); // 2022-02-03T8:45[America/Los_Angeles]
date.subtract({
  minutes: 30
}); // 2022-02-03T09:15[America/Los_Angeles]

Adding or subtracting a duration that goes beyond the limits of a particular field will cause the date to be balanced. For example, adding one day to August 31st results in September 1st. In addition, if adding or subtracting one field causes another to be invalid, the date will be constrained. For example, adding one month to August 31st results in September 30th because September 31st does not exist.

Adding and subtracting is time zone aware. When adjusting a date around a daylight saving time transition, the hour may be adjusted accordingly. For example, in the United States, adding one hour during a "spring forward" transition skips the 2 AM hour, and adding an hour in a "fall back" transition repeats the 1 AM hour. Under the hood, the UTC offset is changing instead.

// A "spring forward" transition
let date = parseZonedDateTime('2020-03-08T01:00-08:00[America/Los_Angeles]');
date.add({hours: 1}); // 2020-03-08T03:00-07:00[America/Los_Angeles]

// A "fall back" transition
let date = parseZonedDateTime('2020-11-01T01:00-07:00[America/Los_Angeles]');
date.add({hours: 1}); // 2020-11-01T01:00-08:00[America/Los_Angeles]
date.add({hours: 2}); // 2020-11-01T02:00-08:00[America/Los_Angeles]

// A "spring forward" transition
let date = parseZonedDateTime(
  '2020-03-08T01:00-08:00[America/Los_Angeles]'
);
date.add({ hours: 1 }); // 2020-03-08T03:00-07:00[America/Los_Angeles]

// A "fall back" transition
let date = parseZonedDateTime(
  '2020-11-01T01:00-07:00[America/Los_Angeles]'
);
date.add({ hours: 1 }); // 2020-11-01T01:00-08:00[America/Los_Angeles]
date.add({ hours: 2 }); // 2020-11-01T02:00-08:00[America/Los_Angeles]

// A "spring forward" transition
let date =
  parseZonedDateTime(
    '2020-03-08T01:00-08:00[America/Los_Angeles]'
  );
date.add({ hours: 1 }); // 2020-03-08T03:00-07:00[America/Los_Angeles]

// A "fall back" transition
let date =
  parseZonedDateTime(
    '2020-11-01T01:00-07:00[America/Los_Angeles]'
  );
date.add({ hours: 1 }); // 2020-11-01T01:00-08:00[America/Los_Angeles]
date.add({ hours: 2 }); // 2020-11-01T02:00-08:00[America/Los_Angeles]

In addition, when changing the date portion of a ZonedDateTime around a daylight saving time transition, the hour may change if it is invalid in the target date. For example, during a "spring forward" transition, the 2 AM hour is skipped.

// A "spring forward" transition
let date = parseZonedDateTime('2020-03-07T02:00-08:00[America/Los_Angeles]');
date.add({days: 1}); // 2020-03-08T03:00-07:00[America/Los_Angeles]

// A "spring forward" transition
let date = parseZonedDateTime(
  '2020-03-07T02:00-08:00[America/Los_Angeles]'
);
date.add({ days: 1 }); // 2020-03-08T03:00-07:00[America/Los_Angeles]

// A "spring forward" transition
let date =
  parseZonedDateTime(
    '2020-03-07T02:00-08:00[America/Los_Angeles]'
  );
date.add({ days: 1 }); // 2020-03-08T03:00-07:00[America/Los_Angeles]

Setting fields#

ZonedDateTime objects are immutable, which means their properties cannot be set directly. Instead, use the set method, and pass the fields to be modified. This will return a new ZonedDateTime with the updated values.

let date = parseZonedDateTime('2022-02-03T09:45[America/Los_Angeles]');
date.set({ day: 10 }); // 2022-02-10T09:45[America/Los_Angeles]
date.set({ month: 5 }); // // 2022-05-03T09:45[America/Los_Angeles]
date.set({ year: 2023, month: 10, day: 16 }); // 2023-10-16T09:45[America/Los_Angeles]
date.set({ hour: 18 }); // 2022-02-03T18:45[America/Los_Angeles]
date.set({ minute: 15 }); // 2022-02-03T09:15[America/Los_Angeles]

let date = parseZonedDateTime(
  '2022-02-03T09:45[America/Los_Angeles]'
);
date.set({ day: 10 }); // 2022-02-10T09:45[America/Los_Angeles]
date.set({ month: 5 }); // // 2022-05-03T09:45[America/Los_Angeles]
date.set({ year: 2023, month: 10, day: 16 }); // 2023-10-16T09:45[America/Los_Angeles]
date.set({ hour: 18 }); // 2022-02-03T18:45[America/Los_Angeles]
date.set({ minute: 15 }); // 2022-02-03T09:15[America/Los_Angeles]

let date =
  parseZonedDateTime(
    '2022-02-03T09:45[America/Los_Angeles]'
  );
date.set({ day: 10 }); // 2022-02-10T09:45[America/Los_Angeles]
date.set({ month: 5 }); // // 2022-05-03T09:45[America/Los_Angeles]
date.set({
  year: 2023,
  month: 10,
  day: 16
}); // 2023-10-16T09:45[America/Los_Angeles]
date.set({ hour: 18 }); // 2022-02-03T18:45[America/Los_Angeles]
date.set({ minute: 15 }); // 2022-02-03T09:15[America/Los_Angeles]

Setting a field to a value that is outside the valid range will cause it to be constrained. For example, setting the day to a value that is greater than the number of days in the month, will result in the last day of the month.

let date = parseZonedDateTime('2022-02-03T09:45[America/Los_Angeles]');
date.set({day: 100}); // 2022-02-28T09:45[America/Los_Angeles]
date.set({month: 20}); // 2022-12-03T09:45[America/Los_Angeles]
date.set({hour: 30}); // 2022-02-03T23:45[America/Los_Angeles]

let date = parseZonedDateTime(
  '2022-02-03T09:45[America/Los_Angeles]'
);
date.set({ day: 100 }); // 2022-02-28T09:45[America/Los_Angeles]
date.set({ month: 20 }); // 2022-12-03T09:45[America/Los_Angeles]
date.set({ hour: 30 }); // 2022-02-03T23:45[America/Los_Angeles]

let date =
  parseZonedDateTime(
    '2022-02-03T09:45[America/Los_Angeles]'
  );
date.set({ day: 100 }); // 2022-02-28T09:45[America/Los_Angeles]
date.set({ month: 20 }); // 2022-12-03T09:45[America/Los_Angeles]
date.set({ hour: 30 }); // 2022-02-03T23:45[America/Los_Angeles]

Setting fields is time zone aware. When setting fields around a daylight saving time transition, the UTC offset will be adjusted accordingly. For example, when changing the day field from before a daylight saving transition to after, the time remains the same but the UTC offset changes.

let date = parseZonedDateTime('2020-03-01T10:00-08:00[America/Los_Angeles]');
date.set({day: 14}); // 2020-03-14T10:00-07:00[America/Los_Angeles]

let date = parseZonedDateTime(
  '2020-03-01T10:00-08:00[America/Los_Angeles]'
);
date.set({ day: 14 }); // 2020-03-14T10:00-07:00[America/Los_Angeles]

let date =
  parseZonedDateTime(
    '2020-03-01T10:00-08:00[America/Los_Angeles]'
  );
date.set({ day: 14 }); // 2020-03-14T10:00-07:00[America/Los_Angeles]

In addition, some time values during daylight saving transitions may be ambiguous. For example, in the United States, the 2 AM hour is skipped in the spring, and the 1 AM hour occurs twice in the fall. When setting date fields, this ambiguity must be resolved to determine the exact time. By default, the later of the two possible times is chosen for "spring forward" transitions, and the earlier time is chosen for "fall back" transitions. This can be controlled by passing the disambiguation parameter to the set method.

'earlier' – choose the earlier of the two possible times
'later' – choose the later of the two possible times
'compatible' (default) – choose the later of the two times during "spring forward" transitions, and the earlier time during "fall back" transitions.
'reject' – throws an error when the time is ambiguous

// A "spring forward" transition
let date = parseZonedDateTime('2020-03-01T02:00-08:00[America/Los_Angeles]');
date.set({ day: 8 }); // 2020-03-08T03:00:00-07:00[America/Los_Angeles]
date.set({ day: 8 }, 'earlier'); // 2020-03-08T01:00:00-08:00[America/Los_Angeles]
date.set({ day: 8 }, 'later'); // 2020-03-08T03:00:00-07:00[America/Los_Angeles]

// A "fall back" transition
let date = parseZonedDateTime('2020-10-01T01:00-07:00[America/Los_Angeles]');
date.set({ month: 11 }); // 2020-11-01T01:00:00-07:00[America/Los_Angeles]
date.set({ month: 11 }, 'earlier'); // 2020-11-01T01:00:00-07:00[America/Los_Angeles]
date.set({ month: 11 }, 'later'); // 2020-11-01T01:00:00-08:00[America/Los_Angeles]

// A "spring forward" transition
let date = parseZonedDateTime(
  '2020-03-01T02:00-08:00[America/Los_Angeles]'
);
date.set({ day: 8 }); // 2020-03-08T03:00:00-07:00[America/Los_Angeles]
date.set({ day: 8 }, 'earlier'); // 2020-03-08T01:00:00-08:00[America/Los_Angeles]
date.set({ day: 8 }, 'later'); // 2020-03-08T03:00:00-07:00[America/Los_Angeles]

// A "fall back" transition
let date = parseZonedDateTime(
  '2020-10-01T01:00-07:00[America/Los_Angeles]'
);
date.set({ month: 11 }); // 2020-11-01T01:00:00-07:00[America/Los_Angeles]
date.set({ month: 11 }, 'earlier'); // 2020-11-01T01:00:00-07:00[America/Los_Angeles]
date.set({ month: 11 }, 'later'); // 2020-11-01T01:00:00-08:00[America/Los_Angeles]

// A "spring forward" transition
let date =
  parseZonedDateTime(
    '2020-03-01T02:00-08:00[America/Los_Angeles]'
  );
date.set({ day: 8 }); // 2020-03-08T03:00:00-07:00[America/Los_Angeles]
date.set(
  { day: 8 },
  'earlier'
); // 2020-03-08T01:00:00-08:00[America/Los_Angeles]
date.set(
  { day: 8 },
  'later'
); // 2020-03-08T03:00:00-07:00[America/Los_Angeles]

// A "fall back" transition
let date =
  parseZonedDateTime(
    '2020-10-01T01:00-07:00[America/Los_Angeles]'
  );
date.set({ month: 11 }); // 2020-11-01T01:00:00-07:00[America/Los_Angeles]
date.set(
  { month: 11 },
  'earlier'
); // 2020-11-01T01:00:00-07:00[America/Los_Angeles]
date.set(
  { month: 11 },
  'later'
); // 2020-11-01T01:00:00-08:00[America/Los_Angeles]

Cycling fields#

The cycle method allows incrementing or decrementing a single field. It is similar to the add and subtract methods, but when the value reaches the minimum or maximum, it wraps around rather than affecting other fields.

let date = parseZonedDateTime('2022-12-31T23:59[America/Los_Angeles]');
date.cycle('day', 1); // 2022-12-01T23:59[America/Los_Angeles]
date.cycle('month', 1); // 2022-01-31T23:59[America/Los_Angeles]
date.cycle('hour', 1); // 2022-12-31T00:59[America/Los_Angeles]
date.cycle('minute', 1); // 2022-12-31T23:00[America/Los_Angeles]

let date = parseZonedDateTime('2022-01-01T00:00[America/Los_Angeles]');
date.cycle('day', -1); // 2022-01-31T00:00[America/Los_Angeles]
date.cycle('month', -1); // 2022-12-01T00:00[America/Los_Angeles]
date.cycle('hour', -1); // 2022-01-01T23:00[America/Los_Angeles]
date.cycle('minute', -1); // 2022-01-01T00:59[America/Los_Angeles]

let date = parseZonedDateTime(
  '2022-12-31T23:59[America/Los_Angeles]'
);
date.cycle('day', 1); // 2022-12-01T23:59[America/Los_Angeles]
date.cycle('month', 1); // 2022-01-31T23:59[America/Los_Angeles]
date.cycle('hour', 1); // 2022-12-31T00:59[America/Los_Angeles]
date.cycle('minute', 1); // 2022-12-31T23:00[America/Los_Angeles]

let date = parseZonedDateTime(
  '2022-01-01T00:00[America/Los_Angeles]'
);
date.cycle('day', -1); // 2022-01-31T00:00[America/Los_Angeles]
date.cycle('month', -1); // 2022-12-01T00:00[America/Los_Angeles]
date.cycle('hour', -1); // 2022-01-01T23:00[America/Los_Angeles]
date.cycle('minute', -1); // 2022-01-01T00:59[America/Los_Angeles]

let date =
  parseZonedDateTime(
    '2022-12-31T23:59[America/Los_Angeles]'
  );
date.cycle('day', 1); // 2022-12-01T23:59[America/Los_Angeles]
date.cycle('month', 1); // 2022-01-31T23:59[America/Los_Angeles]
date.cycle('hour', 1); // 2022-12-31T00:59[America/Los_Angeles]
date.cycle('minute', 1); // 2022-12-31T23:00[America/Los_Angeles]

let date =
  parseZonedDateTime(
    '2022-01-01T00:00[America/Los_Angeles]'
  );
date.cycle('day', -1); // 2022-01-31T00:00[America/Los_Angeles]
date.cycle('month', -1); // 2022-12-01T00:00[America/Los_Angeles]
date.cycle('hour', -1); // 2022-01-01T23:00[America/Los_Angeles]
date.cycle('minute', -1); // 2022-01-01T00:59[America/Los_Angeles]

Note that if cycling a field causes another field to become invalid, the date is constrained. For example, adding one month to August 31st results in September 30th because September 31st does not exist.

The round option may also be passed, which causes the value to be rounded to increments of the given amount. For example, you could round the minute to increments of 15.

let date = parseZonedDateTime('2022-02-03T09:22[America/Los_Angeles]');

date.cycle('minute', 15); // 2027-02-03T09:37[America/Los_Angeles]
date.cycle('minute', 15, { round: true }); // 2025-02-03T09:30[America/Los_Angeles]

date.cycle('minute', -15); // 2017-02-03T09:07[America/Los_Angeles]
date.cycle('minute', -15, { round: true }); // 2020-02-03T09:15[America/Los_Angeles]

let date = parseZonedDateTime(
  '2022-02-03T09:22[America/Los_Angeles]'
);

date.cycle('minute', 15); // 2027-02-03T09:37[America/Los_Angeles]
date.cycle('minute', 15, { round: true }); // 2025-02-03T09:30[America/Los_Angeles]

date.cycle('minute', -15); // 2017-02-03T09:07[America/Los_Angeles]
date.cycle('minute', -15, { round: true }); // 2020-02-03T09:15[America/Los_Angeles]

let date =
  parseZonedDateTime(
    '2022-02-03T09:22[America/Los_Angeles]'
  );

date.cycle('minute', 15); // 2027-02-03T09:37[America/Los_Angeles]
date.cycle(
  'minute',
  15,
  { round: true }
); // 2025-02-03T09:30[America/Los_Angeles]

date.cycle(
  'minute',
  -15
); // 2017-02-03T09:07[America/Los_Angeles]
date.cycle(
  'minute',
  -15,
  { round: true }
); // 2020-02-03T09:15[America/Los_Angeles]

By default, the hour field is cycled within a 24 hour range. The hourCycle option can be set to 12 to use a 12 hour clock instead, which will preserve the AM/PM value when formatted.

let date = parseZonedDateTime('2022-02-03T11:00[America/Los_Angeles]');
date.cycle('hour', 1); // 2022-02-03T12:00[America/Los_Angeles]
date.cycle('hour', 1, {hourCycle: 12}); // 2022-02-03T00:00[America/Los_Angeles]

let date = parseZonedDateTime('2022-02-03T23:00[America/Los_Angeles]');
date.cycle('hour', 1); // 2022-02-03T00:00[America/Los_Angeles]
date.cycle('hour', 1, {hourCycle: 12}); // 2022-02-03T12:00[America/Los_Angeles]

let date = parseZonedDateTime(
  '2022-02-03T11:00[America/Los_Angeles]'
);
date.cycle('hour', 1); // 2022-02-03T12:00[America/Los_Angeles]
date.cycle('hour', 1, { hourCycle: 12 }); // 2022-02-03T00:00[America/Los_Angeles]

let date = parseZonedDateTime(
  '2022-02-03T23:00[America/Los_Angeles]'
);
date.cycle('hour', 1); // 2022-02-03T00:00[America/Los_Angeles]
date.cycle('hour', 1, { hourCycle: 12 }); // 2022-02-03T12:00[America/Los_Angeles]

let date =
  parseZonedDateTime(
    '2022-02-03T11:00[America/Los_Angeles]'
  );
date.cycle('hour', 1); // 2022-02-03T12:00[America/Los_Angeles]
date.cycle('hour', 1, {
  hourCycle: 12
}); // 2022-02-03T00:00[America/Los_Angeles]

let date =
  parseZonedDateTime(
    '2022-02-03T23:00[America/Los_Angeles]'
  );
date.cycle('hour', 1); // 2022-02-03T00:00[America/Los_Angeles]
date.cycle('hour', 1, {
  hourCycle: 12
}); // 2022-02-03T12:00[America/Los_Angeles]

Cycling fields is time zone aware. When adjusting a date around a daylight saving time transition, the hour may be adjusted accordingly. For example, in the United States, adding one hour during a "spring forward" transition skips the 2 AM hour, and adding an hour in a "fall back" transition repeats the 1 AM hour. Under the hood, the UTC offset is changing instead.

// A "spring forward" transition
let date = parseZonedDateTime('2020-03-08T01:00-08:00[America/Los_Angeles]');
date.cycle('hour', 1); // 2020-03-08T03:00-07:00[America/Los_Angeles]

// A "fall back" transition
let date = parseZonedDateTime('2020-11-01T01:00-07:00[America/Los_Angeles]');
date.cycle('hour', 1); // 2020-11-01T01:00-08:00[America/Los_Angeles]

// A "spring forward" transition
let date = parseZonedDateTime(
  '2020-03-08T01:00-08:00[America/Los_Angeles]'
);
date.cycle('hour', 1); // 2020-03-08T03:00-07:00[America/Los_Angeles]

// A "fall back" transition
let date = parseZonedDateTime(
  '2020-11-01T01:00-07:00[America/Los_Angeles]'
);
date.cycle('hour', 1); // 2020-11-01T01:00-08:00[America/Los_Angeles]

// A "spring forward" transition
let date =
  parseZonedDateTime(
    '2020-03-08T01:00-08:00[America/Los_Angeles]'
  );
date.cycle('hour', 1); // 2020-03-08T03:00-07:00[America/Los_Angeles]

// A "fall back" transition
let date =
  parseZonedDateTime(
    '2020-11-01T01:00-07:00[America/Los_Angeles]'
  );
date.cycle('hour', 1); // 2020-11-01T01:00-08:00[America/Los_Angeles]

// A "spring forward" transition
let date = parseZonedDateTime('2020-03-07T02:00-08:00[America/Los_Angeles]');
date.cycle('day', 1); // 2020-03-08T03:00-07:00[America/Los_Angeles]

// A "spring forward" transition
let date = parseZonedDateTime(
  '2020-03-07T02:00-08:00[America/Los_Angeles]'
);
date.cycle('day', 1); // 2020-03-08T03:00-07:00[America/Los_Angeles]

// A "spring forward" transition
let date =
  parseZonedDateTime(
    '2020-03-07T02:00-08:00[America/Los_Angeles]'
  );
date.cycle('day', 1); // 2020-03-08T03:00-07:00[America/Los_Angeles]

Conversion#

To a string#

ZonedDateTime objects can be converted to an ISO 8601 formatted string using the toString method. This format preserves the maximum amount of information, including the UTC offset and time zone identifier, in the same format used in other languages like Java.

let date = new ZonedDateTime(
  2022, 2, 3,
  'America/Los_Angeles', -28800000,
  12, 24, 45
);

date.toString(); // '2022-02-03T12:24:45-08:00[America/Los_Angeles]'

let date = new ZonedDateTime(
  2022,
  2,
  3,
  'America/Los_Angeles',
  -28800000,
  12,
  24,
  45
);

date.toString(); // '2022-02-03T12:24:45-08:00[America/Los_Angeles]'

let date =
  new ZonedDateTime(
    2022,
    2,
    3,
    'America/Los_Angeles',
    -28800000,
    12,
    24,
    45
  );

date.toString(); // '2022-02-03T12:24:45-08:00[America/Los_Angeles]'

If the exact local time and time zone that a user selected is important, use this format. Storing the time zone and offset that was selected rather than converting to UTC ensures that the local time is correct regardless of daylight saving rule changes (e.g. if a locale abolishes DST). Examples where this applies include calendar events, reminders, and other times that occur in a particular location.

You can also use the toAbsoluteString method to convert the date to a UTC string. Use this format if the exact time no matter the time zone is needed.

date.toAbsoluteString(); // '2022-02-03T20:24:45.000Z'

date.toAbsoluteString(); // '2022-02-03T20:24:45.000Z'

date.toAbsoluteString(); // '2022-02-03T20:24:45.000Z'

To a native Date object#

A ZonedDateTime can be converted to a native JavaScript Date object using the toDate method. In general, the Date object should be avoided because it has many internationalization issues and other flaws. However, it is necessary to use some functionality like date formatting.

let date = parseZonedDateTime('2022-02-03T09:45[America/Los_Angeles]');
date.toDate('America/Los_Angeles'); // Thu Feb 03 2022 09:45:00 GMT-0800 (Pacific Standard Time)

let date = parseZonedDateTime(
  '2022-02-03T09:45[America/Los_Angeles]'
);
date.toDate('America/Los_Angeles'); // Thu Feb 03 2022 09:45:00 GMT-0800 (Pacific Standard Time)

let date =
  parseZonedDateTime(
    '2022-02-03T09:45[America/Los_Angeles]'
  );
date.toDate(
  'America/Los_Angeles'
); // Thu Feb 03 2022 09:45:00 GMT-0800 (Pacific Standard Time)

To a date or time only#

A ZonedDateTime can be converted to a CalendarDate or Time object if only one of these components is needed.

Use the toCalendarDate function to convert a ZonedDateTime to a CalendarDate.

import {toCalendarDate} from '@internationalized/date';

let date = parseZonedDateTime('2022-02-03T09:45[America/Los_Angeles]');
toCalendarDate(date); // 2022-02-03

import {toCalendarDate} from '@internationalized/date';

let date = parseZonedDateTime(
  '2022-02-03T09:45[America/Los_Angeles]'
);
toCalendarDate(date); // 2022-02-03

import {toCalendarDate} from '@internationalized/date';

let date =
  parseZonedDateTime(
    '2022-02-03T09:45[America/Los_Angeles]'
  );
toCalendarDate(date); // 2022-02-03

Use the toTime function to convert a ZonedDateTime to a Time.

import {toTime} from '@internationalized/date';

let date = parseZonedDateTime('2022-02-03T09:45[America/Los_Angeles]');
toTime(date); // 09:45

import {toTime} from '@internationalized/date';

let date = parseZonedDateTime(
  '2022-02-03T09:45[America/Los_Angeles]'
);
toTime(date); // 09:45

import {toTime} from '@internationalized/date';

let date =
  parseZonedDateTime(
    '2022-02-03T09:45[America/Los_Angeles]'
  );
toTime(date); // 09:45

To a date and time without a time zone#

A ZonedDateTime can be converted to a CalendarDateTime, which represents a date and time that is not in any specific time zone. Use this type to represent times that occur at the same local time regardless of the time zone, such as the time of New Years Eve fireworks which always occur at midnight. Most times are better stored as a ZonedDateTime.

Use the toCalendarDateTime function to convert a ZonedDateTime to a CalendarDateTime.

import {toCalendarDateTime} from '@internationalized/date';

let date = parseZonedDateTime('2022-02-03T09:45[America/Los_Angeles]');
toCalendarDateTime(date); // 2022-02-03T09:45:00

import {toCalendarDateTime} from '@internationalized/date';

let date = parseZonedDateTime(
  '2022-02-03T09:45[America/Los_Angeles]'
);
toCalendarDateTime(date); // 2022-02-03T09:45:00

import {toCalendarDateTime} from '@internationalized/date';

let date =
  parseZonedDateTime(
    '2022-02-03T09:45[America/Los_Angeles]'
  );
toCalendarDateTime(date); // 2022-02-03T09:45:00

Between time zones#

A ZonedDateTime can be converted to a different time zone using the toTimeZone function. The toLocalTimeZone function can also be used to convert to the current user's local time zone.

import {toTimeZone, toLocalTimeZone} from '@internationalized/date';

let date = parseZonedDateTime('2022-02-03T09:45[America/Los_Angeles]');
toTimeZone(date, 'America/Chicago'); // 2022-02-03T11:45[America/Chicago]
toLocalTimeZone(date); // e.g. 2022-02-03T12:45[America/New_York]

import {
  toLocalTimeZone,
  toTimeZone
} from '@internationalized/date';

let date = parseZonedDateTime(
  '2022-02-03T09:45[America/Los_Angeles]'
);
toTimeZone(date, 'America/Chicago'); // 2022-02-03T11:45[America/Chicago]
toLocalTimeZone(date); // e.g. 2022-02-03T12:45[America/New_York]

import {
  toLocalTimeZone,
  toTimeZone
} from '@internationalized/date';

let date =
  parseZonedDateTime(
    '2022-02-03T09:45[America/Los_Angeles]'
  );
toTimeZone(
  date,
  'America/Chicago'
); // 2022-02-03T11:45[America/Chicago]
toLocalTimeZone(date); // e.g. 2022-02-03T12:45[America/New_York]

Queries#

Comparison#

ZonedDateTime objects can be compared either for full or partial equality, or in order to determine which date is before or after another.

The compare method can be used to determine if a date is before or after another. It returns a number less than zero if the first date is before the second, zero if the values are equal, or a number greater than zero if the first date is after the second.

let a = parseZonedDateTime('2022-02-03T09:45[America/Los_Angeles]');
let b = parseZonedDateTime('2022-03-04T09:45[America/Los_Angeles]');

a.compare(b) < 0; // true
b.compare(a) > 0; // true

let a = parseZonedDateTime(
  '2022-02-03T09:45[America/Los_Angeles]'
);
let b = parseZonedDateTime(
  '2022-03-04T09:45[America/Los_Angeles]'
);

a.compare(b) < 0; // true
b.compare(a) > 0; // true

let a =
  parseZonedDateTime(
    '2022-02-03T09:45[America/Los_Angeles]'
  );
let b =
  parseZonedDateTime(
    '2022-03-04T09:45[America/Los_Angeles]'
  );

a.compare(b) < 0; // true
b.compare(a) > 0; // true

In addition, the following functions can be used to perform a partial comparison. These functions accept dates in different calendar systems, and the second date is converted to the calendar system of the first date before comparison.

isSameYear – Returns whether the given dates occur in the same year, using the calendar system of the first date.
isSameMonth – Returns whether the given dates occur in the same month, using the calendar system of the first date.
isSameDay – Returns whether the given dates occur on the same day, regardless of the time or calendar system.
isToday – Returns whether the date is today in the given time zone.

import {isSameMonth} from '@internationalized/date';

isSameMonth(
  parseZonedDateTime('2022-04-16T09:45[America/Los_Angeles]'),
  parseZonedDateTime('2022-04-30T05:15[America/Los_Angeles]'),
); // true

isSameMonth(
  parseZonedDateTime('2022-04-16T09:45[America/Los_Angeles]'),
  parseZonedDateTime('2022-08-020T05:15[America/Los_Angeles]'),
); // false

import {isSameMonth} from '@internationalized/date';

isSameMonth(
  parseZonedDateTime(
    '2022-04-16T09:45[America/Los_Angeles]'
  ),
  parseZonedDateTime(
    '2022-04-30T05:15[America/Los_Angeles]'
  )
); // true

isSameMonth(
  parseZonedDateTime(
    '2022-04-16T09:45[America/Los_Angeles]'
  ),
  parseZonedDateTime(
    '2022-08-020T05:15[America/Los_Angeles]'
  )
); // false

import {isSameMonth} from '@internationalized/date';

isSameMonth(
  parseZonedDateTime(
    '2022-04-16T09:45[America/Los_Angeles]'
  ),
  parseZonedDateTime(
    '2022-04-30T05:15[America/Los_Angeles]'
  )
); // true

isSameMonth(
  parseZonedDateTime(
    '2022-04-16T09:45[America/Los_Angeles]'
  ),
  parseZonedDateTime(
    '2022-08-020T05:15[America/Los_Angeles]'
  )
); // false

A similar set of functions is also available that does not convert between calendar systems and requires the calendars to be equal.

isEqualYear – Returns whether the given dates occur in the same year, and are of the same calendar system.
isEqualMonth – Returns whether the given dates occur in the same month, and are of the same calendar system.
isEqualDay – Returns whether the given dates occur on the same day, and are of the same calendar system.

Start and end dates#

The following functions can be used to find the start or end dates of a particular unit of time. These only affect the date components of a ZonedDateTime. The time fields are left unchanged.

startOfYear – Returns the first day of the year for the given date.
endOfYear – Returns the last day of the year for the given date.
startOfMonth – Returns the first date of the month for the given date.
endOfMonth – Returns the last date of the month for the given date.
startOfWeek – Returns the first date of the week for the given date and locale.
endOfWeek – Returns the last date of the week for the given date and locale.

Note that startOfWeek and endOfWeek require a locale string to be provided. This is because the first day of the week changes depending on the locale. For example, in the United States, the first day of the week is on Sunday, but in France it is on Monday.

import {startOfYear, startOfMonth, startOfWeek} from '@internationalized/date';

let date = parseZonedDateTime('2022-02-03T09:45[America/Los_Angeles]');

startOfYear(date); // 2022-01-01T09:45[America/Los_Angeles]
startOfMonth(date); // 2022-02-01T09:45[America/Los_Angeles]
startOfWeek(date, 'en-US'); // 2022-01-30T09:45[America/Los_Angeles]
startOfWeek(date, 'fr-FR'); // 2022-01-31T09:45[America/Los_Angeles]

import {
  startOfMonth,
  startOfWeek,
  startOfYear
} from '@internationalized/date';

let date = parseZonedDateTime(
  '2022-02-03T09:45[America/Los_Angeles]'
);

startOfYear(date); // 2022-01-01T09:45[America/Los_Angeles]
startOfMonth(date); // 2022-02-01T09:45[America/Los_Angeles]
startOfWeek(date, 'en-US'); // 2022-01-30T09:45[America/Los_Angeles]
startOfWeek(date, 'fr-FR'); // 2022-01-31T09:45[America/Los_Angeles]

import {
  startOfMonth,
  startOfWeek,
  startOfYear
} from '@internationalized/date';

let date =
  parseZonedDateTime(
    '2022-02-03T09:45[America/Los_Angeles]'
  );

startOfYear(date); // 2022-01-01T09:45[America/Los_Angeles]
startOfMonth(date); // 2022-02-01T09:45[America/Los_Angeles]
startOfWeek(
  date,
  'en-US'
); // 2022-01-30T09:45[America/Los_Angeles]
startOfWeek(
  date,
  'fr-FR'
); // 2022-01-31T09:45[America/Los_Angeles]

Day of week#

The getDayOfWeek function returns the day of the week for the given date and locale. Days are numbered from zero to six, where zero is the first day of the week in the given locale. For example, in the United States, the first day of the week is Sunday, but in France it is Monday.

import {getDayOfWeek} from '@internationalized/date';

let date = parseZonedDateTime('2022-02-06T08:30[America/Los_Angeles]'); // a Sunday

getDayOfWeek(date, 'en-US'); // 0
getDayOfWeek(locale, 'fr-FR'); // 6

import {getDayOfWeek} from '@internationalized/date';

let date = parseZonedDateTime(
  '2022-02-06T08:30[America/Los_Angeles]'
); // a Sunday

getDayOfWeek(date, 'en-US'); // 0
getDayOfWeek(locale, 'fr-FR'); // 6

import {getDayOfWeek} from '@internationalized/date';

let date =
  parseZonedDateTime(
    '2022-02-06T08:30[America/Los_Angeles]'
  ); // a Sunday

getDayOfWeek(
  date,
  'en-US'
); // 0
getDayOfWeek(
  locale,
  'fr-FR'
); // 6

Weekdays and weekends#

The isWeekday and isWeekend functions can be used to determine if a date is weekday or weekend respectively. This depends on the locale. For example, in the United States, weekends are Saturday and Sunday, but in Israel they are Friday and Saturday.

import {isWeekday, isWeekend} from '@internationalized/date';

let date = parseZonedDateTime('2022-02-06T08:30[America/Los_Angeles]'); // a Sunday

isWeekday(date, 'en-US'); // false
isWeekday(date, 'he-IL'); // true

isWeekend(date, 'en-US'); // true
isWeekday(date, 'he-IL'); // false

import {
  isWeekday,
  isWeekend
} from '@internationalized/date';

let date = parseZonedDateTime(
  '2022-02-06T08:30[America/Los_Angeles]'
); // a Sunday

isWeekday(date, 'en-US'); // false
isWeekday(date, 'he-IL'); // true

isWeekend(date, 'en-US'); // true
isWeekday(date, 'he-IL'); // false

import {
  isWeekday,
  isWeekend
} from '@internationalized/date';

let date =
  parseZonedDateTime(
    '2022-02-06T08:30[America/Los_Angeles]'
  ); // a Sunday

isWeekday(date, 'en-US'); // false
isWeekday(date, 'he-IL'); // true

isWeekend(date, 'en-US'); // true
isWeekday(date, 'he-IL'); // false

Weeks in month#

The getWeeksInMonth function returns the number of weeks in the given month. This depends on the number of days in the month, what day of the week the month starts on, and the given locale. For example, in the United States, the first day of the week is Sunday, but in France it is Monday.

import {getWeeksInMonth} from '@internationalized/date';

let date = parseZonedDateTime('2022-01-01T08:30[America/Los_Angeles]');

getWeeksInMonth(date, 'en-US'); // 6
getWeeksInMonth(date, 'fr-FR'); // 5

import {getWeeksInMonth} from '@internationalized/date';

let date = parseZonedDateTime(
  '2022-01-01T08:30[America/Los_Angeles]'
);

getWeeksInMonth(date, 'en-US'); // 6
getWeeksInMonth(date, 'fr-FR'); // 5

import {getWeeksInMonth} from '@internationalized/date';

let date =
  parseZonedDateTime(
    '2022-01-01T08:30[America/Los_Angeles]'
  );

getWeeksInMonth(
  date,
  'en-US'
); // 6
getWeeksInMonth(
  date,
  'fr-FR'
); // 5

Parses an ISO 8601 date and time string with a time zone extension and optional UTC offset (e.g. "2021-11-07T00:45[America/LosAngeles]" or "2021-11-07T00:45-07:00[America/LosAngeles]"). Ambiguous times due to daylight saving time transitions are resolved according to the disambiguation parameter.

parseZonedDateTime(
  (value: string,
  , disambiguation?: Disambiguation
)): ZonedDateTime

'compatible'
  | 'earlier'
  | 'later'
  | 'reject'

A ZonedDateTime represents a date and time in a specific time zone and calendar system.

Properties

Name	Type	Description
`calendar`	`Calendar`	The calendar system associated with this date, e.g. Gregorian.
`era`	`string`	The calendar era for this date, e.g. "BC" or "AD".
`year`	`number`	The year of this date within the era.
`month`	`number`	The month number within the year. Note that some calendar systems such as Hebrew may have a variable number of months per year. Therefore, month numbers may not always correspond to the same month names in different years.
`day`	`number`	The day number within the month.
`hour`	`number`	The hour in the day, numbered from 0 to 23.
`minute`	`number`	The minute in the hour.
`second`	`number`	The second in the minute.
`millisecond`	`number`	The millisecond in the second.
`timeZone`	`string`	The IANA time zone identifier that this date and time is represented in.
`offset`	`number`	The UTC offset for this time, in seconds.

Methods

Method	Description
`constructor( (...args: any[] )): void`
`copy(): ZonedDateTime`	Returns a copy of this date.
`add( (duration: DateTimeDuration )): void`	Returns a new `ZonedDateTime` with the given duration added to it.
`subtract( (duration: DateTimeDuration )): void`	Returns a new `ZonedDateTime` with the given duration subtracted from it.
`set( (fields: DateFields & & TimeFields, , disambiguation?: Disambiguation )): void`	Returns a new `ZonedDateTime` with the given fields set to the provided values. Other fields will be constrained accordingly.
`cycle( field: DateField \| \| TimeField, amount: number, options?: CycleTimeOptions ): void`	Returns a new `ZonedDateTime` with the given field adjusted by a specified amount. When the resulting value reaches the limits of the field, it wraps around.
`toDate(): void`	Converts the date to a native JavaScript Date object.
`toString(): void`	Converts the date to an ISO 8601 formatted string, including the UTC offset and time zone identifier.
`toAbsoluteString(): void`	Converts the date to an ISO 8601 formatted string in UTC.
`compare( (b: CalendarDate \| CalendarDateTime \| ZonedDateTime )): void`	Compares this date with another. A negative result indicates that this date is before the given one, and a positive date indicates that it is after.

The Calendar interface represents a calendar system, including information about how days, months, years, and eras are organized, and methods to perform arithmetic on dates.

Properties

Name	Type	Description
`identifier`	`string`	A string identifier for the calendar, as defined by Unicode CLDR.

Methods

Method	Description
`fromJulianDay( (jd: number )): CalendarDate`	Creates a CalendarDate in this calendar from the given Julian day number.
`toJulianDay( (date: AnyCalendarDate )): number`	Converts a date in this calendar to a Julian day number.
`getDaysInMonth( (date: AnyCalendarDate )): number`	Returns the number of days in the month of the given date.
`getMonthsInYear( (date: AnyCalendarDate )): number`	Returns the number of months in the year of the given date.
`getYearsInEra( (date: AnyCalendarDate )): number`	Returns the number of years in the era of the given date.
`getEras(): string[]`	Returns a list of era identifiers for the calendar.
`getMinimumMonthInYear( (date: AnyCalendarDate )): number`	Returns the minimum month number of the given date's year. Normally, this is 1, but in some calendars such as the Japanese, eras may begin in the middle of a year.
`getMinimumDayInMonth( (date: AnyCalendarDate )): number`	Returns the minimum day number of the given date's month. Normally, this is 1, but in some calendars such as the Japanese, eras may begin in the middle of a month.

Name	Type	Description
`calendar`	`Calendar`
`era`	`string`
`year`	`number`
`month`	`number`
`day`	`number`

Method	Description
`copy():`

Represents an amount of time with both date and time components, for use when performing arithmetic.

Name	Type	Description
`years`	`number`	The number of years to add or subtract.
`months`	`number`	The number of months to add or subtract.
`weeks`	`number`	The number of weeks to add or subtract.
`days`	`number`	The number of days to add or subtract.
`hours`	`number`	The number of hours to add or subtract.
`minutes`	`number`	The number of minutes to add or subtract.
`seconds`	`number`	The number of seconds to add or subtract.
`milliseconds`	`number`	The number of milliseconds to add or subtract.

Name	Type	Description
`era`	`string`
`year`	`number`
`month`	`number`
`day`	`number`

Name	Type	Description
`hour`	`number`
`minute`	`number`
`second`	`number`
`millisecond`	`number`

'era'
  | 'year'
  | 'month'
  | 'day'

'hour'
  | 'minute'
  | 'second'
  | 'millisecond'

Name	Type	Default	Description
`hourCycle`	`12 \| 24`	`24`	Whether to use 12 or 24 hour time. If 12 hour time is chosen, the resulting value will remain in the same day period as the original value (e.g. if the value is AM, the resulting value also be AM).
`round`	`boolean`	—	Whether to round the field value to the nearest interval of the amount.

A CalendarDate represents a date without any time components in a specific calendar system.

Properties

Name	Type	Description
`calendar`	`Calendar`	The calendar system associated with this date, e.g. Gregorian.
`era`	`string`	The calendar era for this date, e.g. "BC" or "AD".
`year`	`number`	The year of this date within the era.
`month`	`number`	The month number within the year. Note that some calendar systems such as Hebrew may have a variable number of months per year. Therefore, month numbers may not always correspond to the same month names in different years.
`day`	`number`	The day number within the month.

Methods

Method	Description
`constructor( (...args: any[] )): void`
`copy(): CalendarDate`	Returns a copy of this date.
`add( (duration: DateDuration )): CalendarDate`	Returns a new `CalendarDate` with the given duration added to it.
`subtract( (duration: DateDuration )): CalendarDate`	Returns a new `CalendarDate` with the given duration subtracted from it.
`set( (fields: DateFields )): CalendarDate`	Returns a new `CalendarDate` with the given fields set to the provided values. Other fields will be constrained accordingly.
`cycle( field: DateField, amount: number, options?: CycleOptions ): CalendarDate`	Returns a new `CalendarDate` with the given field adjusted by a specified amount. When the resulting value reaches the limits of the field, it wraps around.
`toDate( (timeZone: string )): Date`	Converts the date to a native JavaScript Date object, with the time set to midnight in the given time zone.
`toString(): string`	Converts the date to an ISO 8601 formatted string.
`compare( (b: AnyCalendarDate )): number`	Compares this date with another. A negative result indicates that this date is before the given one, and a positive date indicates that it is after.

Represents an amount of time in calendar-specific units, for use when performing arithmetic.

Name	Type	Description
`years`	`number`	The number of years to add or subtract.
`months`	`number`	The number of months to add or subtract.
`weeks`	`number`	The number of weeks to add or subtract.
`days`	`number`	The number of days to add or subtract.

Name	Type	Description
`round`	`boolean`	Whether to round the field value to the nearest interval of the amount.

A CalendarDateTime represents a date and time without a time zone, in a specific calendar system.

Properties

Name	Type	Description
`calendar`	`Calendar`	The calendar system associated with this date, e.g. Gregorian.
`era`	`string`	The calendar era for this date, e.g. "BC" or "AD".
`year`	`number`	The year of this date within the era.
`month`	`number`	The month number within the year. Note that some calendar systems such as Hebrew may have a variable number of months per year. Therefore, month numbers may not always correspond to the same month names in different years.
`day`	`number`	The day number within the month.
`hour`	`number`	The hour in the day, numbered from 0 to 23.
`minute`	`number`	The minute in the hour.
`second`	`number`	The second in the minute.
`millisecond`	`number`	The millisecond in the second.

Methods

Method	Description
`constructor( (...args: any[] )): void`
`copy(): CalendarDateTime`	Returns a copy of this date.
`add( (duration: DateTimeDuration )): CalendarDateTime`	Returns a new `CalendarDateTime` with the given duration added to it.
`subtract( (duration: DateTimeDuration )): CalendarDateTime`	Returns a new `CalendarDateTime` with the given duration subtracted from it.
`set( (fields: DateFields & & TimeFields )): CalendarDateTime`	Returns a new `CalendarDateTime` with the given fields set to the provided values. Other fields will be constrained accordingly.
`cycle( field: DateField \| \| TimeField, amount: number, options?: CycleTimeOptions ): CalendarDateTime`	Returns a new `CalendarDateTime` with the given field adjusted by a specified amount. When the resulting value reaches the limits of the field, it wraps around.
`toDate( (timeZone: string, , disambiguation?: Disambiguation )): Date`	Converts the date to a native JavaScript Date object in the given time zone.
`toString(): string`	Converts the date to an ISO 8601 formatted string.
`compare( (b: CalendarDate \| CalendarDateTime \| ZonedDateTime )): number`	Compares this date with another. A negative result indicates that this date is before the given one, and a positive date indicates that it is after.

Parses an ISO 8601 date and time string with a UTC offset (e.g. "2021-11-07T07:45:00Z" or "2021-11-07T07:45:00-07:00"). The result is converted to the provided time zone.

parseAbsolute(
  (value: string,
  , timeZone: string
)): ZonedDateTime

Parses an ISO 8601 date and time string with a UTC offset (e.g. "2021-11-07T07:45:00Z" or "2021-11-07T07:45:00-07:00"). The result is converted to the user's local time zone.

parseAbsoluteToLocal(
  (value: string
)): ZonedDateTime

Converts a date from one calendar system to another.

toCalendar<T extends AnyCalendarDate>(
  (date: T,
  , calendar: Calendar
)): T

Converts a value with date components such as a CalendarDateTime or ZonedDateTime into a CalendarDate.

toCalendarDate(
  (dateTime: AnyCalendarDate
)): CalendarDate

Extracts the time components from a value containing a date and time.

toTime(
  (dateTime: CalendarDateTime
    |  | ZonedDateTime
)): Time

A Time represents a clock time without any date components.

Properties

Name	Type	Description
`hour`	`number`	The hour, numbered from 0 to 23.
`minute`	`number`	The minute in the hour.
`second`	`number`	The second in the minute.
`millisecond`	`number`	The millisecond in the second.

Methods

Method	Description
`constructor( hour: number, minute: number, second: number, millisecond: number ): void`
`copy(): Time`	Returns a copy of this time.
`add( (duration: TimeDuration )): void`	Returns a new `Time` with the given duration added to it.
`subtract( (duration: TimeDuration )): void`	Returns a new `Time` with the given duration subtracted from it.
`set( (fields: TimeFields )): void`	Returns a new `Time` with the given fields set to the provided values. Other fields will be constrained accordingly.
`cycle( field: TimeField, amount: number, options?: CycleTimeOptions ): void`	Returns a new `Time` with the given field adjusted by a specified amount. When the resulting value reaches the limits of the field, it wraps around.
`toString(): void`	Converts the time to an ISO 8601 formatted string.
`compare( (b: AnyTime )): void`	Compares this time with another. A negative result indicates that this time is before the given one, and a positive time indicates that it is after.

Represents an amount of time, for use whe performing arithmetic.

Name	Type	Description
`hours`	`number`	The number of hours to add or subtract.
`minutes`	`number`	The number of minutes to add or subtract.
`seconds`	`number`	The number of seconds to add or subtract.
`milliseconds`	`number`	The number of milliseconds to add or subtract.

Name	Type	Description
`hour`	`number`
`minute`	`number`
`second`	`number`
`millisecond`	`number`

Method	Description
`copy():`

Converts a date value to a CalendarDateTime. An optional Time value can be passed to set the time of the resulting value, otherwise it will default to midnight.

toCalendarDateTime(
  (date: CalendarDate
  | CalendarDateTime
  | ZonedDateTime,
  , time?: AnyTime
)): CalendarDateTime

Converts a ZonedDateTime from one time zone to another.

toTimeZone(
  (date: ZonedDateTime,
  , timeZone: string
)): ZonedDateTime

Converts the given ZonedDateTime into the user's local time zone.

toLocalTimeZone(
  (date: ZonedDateTime
)): ZonedDateTime

Returns whether the given dates occur in the same year, using the calendar system of the first date.

isSameYear(
  (a: DateValue,
  , b: DateValue
)): boolean

CalendarDate
  | CalendarDateTime
  | ZonedDateTime

Returns whether the given dates occur in the same month, using the calendar system of the first date.

isSameMonth(
  (a: DateValue,
  , b: DateValue
)): boolean

Returns whether the given dates occur on the same day, regardless of the time or calendar system.

isSameDay(
  (a: DateValue,
  , b: DateValue
)): boolean

Returns whether the date is today in the given time zone.

isToday(
  (date: DateValue,
  , timeZone: string
)): boolean

Returns whether the given dates occur in the same year, and are of the same calendar system.

isEqualYear(
  (a: DateValue,
  , b: DateValue
)): boolean

Returns whether the given dates occur in the same month, and are of the same calendar system.

isEqualMonth(
  (a: DateValue,
  , b: DateValue
)): boolean

Returns whether the given dates occur on the same day, and are of the same calendar system.

isEqualDay(
  (a: DateValue,
  , b: DateValue
)): boolean

Returns the first day of the year for the given date.

startOfYear(
  (date: DateValue
)): DateValue

Returns the last day of the year for the given date.

endOfYear(
  (date: DateValue
)): DateValue

Returns the first date of the month for the given date.

startOfMonth(
  (date: DateValue
)): DateValue

Returns the last date of the month for the given date.

endOfMonth(
  (date: DateValue
)): DateValue

Returns the first date of the week for the given date and locale.

startOfWeek(
  (date: DateValue,
  , locale: string
)): DateValue

Returns the last date of the week for the given date and locale.

endOfWeek(
  (date: DateValue,
  , locale: string
)): DateValue

Returns the day of week for the given date and locale. Days are numbered from zero to six, where zero is the first day of the week in the given locale. For example, in the United States, the first day of the week is Sunday, but in France it is Monday.

getDayOfWeek(
  (date: DateValue,
  , locale: string
)): number

Returns whether the given date is on a weekday in the given locale.

isWeekday(
  (date: DateValue,
  , locale: string
)): boolean

Returns whether the given date is on a weekend in the given locale.

isWeekend(
  (date: DateValue,
  , locale: string
)): boolean

Returns the number of weeks in the given month and locale.

getWeeksInMonth(
  (date: DateValue,
  , locale: string
)): number