JavaScript Temporal ZonedDateTime
Temporal.ZonedDateTime Object Reference
A Temporal.ZonedDateTime is a timezone and calendar-aware date/time object that represents a real time event from the perspective of a particular region on Earth.
It is optimized for cases that require a time zone, DST-safe arithmetic and interoperability with an RFC 5545 calendar.
Example
Example: December 7th, 1995 at 3:24:30 AM in US Pacific time (in Gregorian calendar).
const zonedDate = Temporal.ZonedDateTime.from({
timeZone: 'America/Los_Angeles',
year: 1995,
month: 12,
day: 7,
hour: 3,
minute: 24,
second: 30,
millisecond: 0,
microsecond: 3,
nanosecond: 500
});
Try it Yourself »
Temporal.ZonedDateTime Methods
Revised March 2026
| Method | Description |
|---|---|
| from() | Returns a new ZonedDateTime object from an object or a string |
| getTimeZone Transition() | Returns a ZonedDateTime object representing the closest instant after or before this instant |
| startOfDay() | Returns a ZonedDateTime object representing the first instant of this date |
| toInstant() | Returns a new Instant object representing this date-time |
| toPlainDate() | Returns a new PlainDate object representing this date-time |
| toPlainDateTime() | Returns a new PlainDateTime object representing this date-time |
| toPlainTime() | Returns a new PlainTime object representing this date-time |
| with() | Returns a new ZonedDateTime with specified fields modified |
| withCalendar() | Returns a new ZonedDateTime with a different calendar system |
| withPlainTime() | Returns a new ZonedDateTime the time part replaced by a new time |
| withTimeZone() | Returns a new ZonedDateTime object representing this date-time in the new time zone |
| Arithmetic | |
| add() | Returns a new ZonedDateTime with a duration added |
| subtract() | Returns a new ZonedDateTime with a duration subtracted |
| round() | Returns a new ZonedDateTime rounded to a given unit |
| Comparison | |
| compare() | Returns -1, 0, or 1 from comparing two dates |
| equals() | Returns true if two ZonedDateTime objects are identical |
| since() | Returns the difference from another date |
| until() | Returns the difference until another date |
| Formatting | |
| toString() | Returns an ISO 8601 string representation |
| toJSON() | Returns an ISO 8601 string for JSON serialization |
| toLocaleString() | Returns a language-sensitive representation of the date |
| valueOf() | Throws a TypeError (prevents temporals from being converted to primitives) |
Temporal.ZonedDateTime Properties
| Property | Description |
| calendarID | Calendar system identifier ("iso8601") |
| day | The day as an integer (1-31) |
| dayOfWeek | The day of the week as an integer (1 = Monday) |
| dayOfYear | The ordinal day of the year |
| daysInMonth | The total number of days in that month |
| daysInWeek | The total number of days in that week |
| daysInYear | The total number of days in that year |
| epochMilliseconds | Number of milliseconds since Unix epoch |
| epochNanoseconds | Number of nanoseconds since Unix epoch |
| era | The era name of the calendar, if applicable ("gregory") |
| eraYear | The year within the era, if applicable |
| hour | The hour as an integer (0-23) |
| hoursInDay | Hours in this day in this time zone(0-25) |
| inLeapYear | A boolean indicating if the date falls in a leap year |
| microsecond | The microsecond as an integer (0-999) |
| millisecond | The millisecond as an integer (0-999) |
| minute | The minute as an integer (0-59) |
| month | The month as an integer (1-12) |
| monthCode | A calendar-specific string code for the month ("M01") |
| monthsInYear | The total number of months in that year |
| nanosecond | The nanosecond as an integer (0-999) |
| offset | Offset used to interpret this instant (+HH:mm:ss.sssssssss) |
| offsetNanoseconds | Offset used to interpret this instant in nanoseconds |
| second | The second as an integer (0-59) |
| timeZoneId | Time zone identifier used to interpret this instant |
| weekOfYear | The week number within the year |
| year | The year as an integer |
| yearOfWeek | The year that the week belongs to |
Learn More:
Browser Support
Temporal is a major update to the JavaScript standard (TC39).
It is currently fully supported in Chrome, Edge, and Firefox, and is expected to reach full availability across browsers before the summer of 2026.
| Chrome 144 |
Edge 144 |
Firefox 139 |
Safari |
Opera |
| Jan 2026 | Jan 2026 | May 2025 | 🚫 | 🚫 |
Opera and Safari Support
Opera support will probably appear 1-3 browser cycles after Chromium, which often means a few months later.
The implementation is actively in development and can be tested today in Safari Technology Preview by enabling the --use-temporal runtime flag.
Polyfill
Until Opera and Safari supports Temporal natively, you can use the official polyfill:
<script
src="https://cdn.jsdelivr.net/npm/@js-temporal/polyfill/dist/index.umd.js">
</script>
