Temporal.Now

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The Temporal.Now object provides methods for getting the current time in various formats.

Description

Unlike most global objects, Temporal.Now is not a constructor. You cannot use it with the new operator or invoke the Temporal.Now object as a function. All properties and methods of Temporal.Now are static (just like the Math object).

Most fundamentally, the system time is returned by the operating system as a time since the Unix epoch (usually millisecond-level precision, but might be nanosecond-level too). Temporal.Now.instant() returns this time as a Temporal.Instant object.

An instant can be interpreted in a time zone (which is the system time zone Temporal.Now.timeZoneId() by default) in the same fashion as Temporal.Instant.prototype.toZonedDateTimeISO(). To get a Temporal.ZonedDateTime object, you can use Temporal.Now.zonedDateTimeISO(). You can also get different parts of the date and time, using Temporal.Now.plainDateISO(), Temporal.Now.plainTimeISO(), and Temporal.Now.plainDateTimeISO().

For example, if the computer is set to the time zone "America/New_York", Temporal.Now.zonedDateTimeISO() returns a zoned date-time like: 2021-08-01T10:40:12.345-04:00[America/New_York]. In this case, Temporal.Now.plainTimeISO() would return the time part of this zoned date-time: 10:40:12.345. However, if you call Temporal.Now.plainTimeISO("UTC"), it returns the time part of the zoned date-time in the UTC time zone: 14:40:12.345. This is especially useful for cross-system communication where the other end may be expecting the time in a different time zone.

Reduced time precision

To offer protection against timing attacks and fingerprinting, the precision of the Temporal.Now functions might get rounded depending on browser settings. In Firefox, the privacy.reduceTimerPrecision preference is enabled by default and defaults to 2ms. You can also enable privacy.resistFingerprinting, in which case the precision will be 100ms or the value of privacy.resistFingerprinting.reduceTimerPrecision.microseconds, whichever is larger.

For example, with reduced time precision, the result of Temporal.Now.instant().epochMilliseconds will always be a multiple of 2, or a multiple of 100 (or privacy.resistFingerprinting.reduceTimerPrecision.microseconds) with privacy.resistFingerprinting enabled.

js
// reduced time precision (2ms) in Firefox 60
Temporal.Now.instant().epochMilliseconds;
// Might be:
// 1519211809934
// 1519211810362
// 1519211811670
// …

// reduced time precision with `privacy.resistFingerprinting` enabled
Temporal.Now.instant().epochMilliseconds;
// Might be:
// 1519129853500
// 1519129858900
// 1519129864400
// …

Static properties

Temporal.Now[Symbol.toStringTag]

The initial value of the [Symbol.toStringTag] property is the string "Temporal.Now". This property is used in Object.prototype.toString().

Static methods

Temporal.Now.instant()

Returns the current time as a Temporal.Instant object.

Temporal.Now.plainDateISO()

Returns the current date as a Temporal.PlainDate object, in the ISO 8601 calendar and the specified time zone.

Temporal.Now.plainDateTimeISO()

Returns the current date and time as a Temporal.PlainDateTime object, in the ISO 8601 calendar and the specified time zone.

Temporal.Now.plainTimeISO()

Returns the current time as a Temporal.PlainTime object, in the specified time zone.

Temporal.Now.timeZoneId()

Returns a time zone identifier representing the system's current time zone.

Temporal.Now.zonedDateTimeISO()

Returns the current date and time as a Temporal.ZonedDateTime object, in the ISO 8601 calendar and the specified time zone.

Specifications

Specification
Temporal proposal
# sec-temporal-now-object

Browser compatibility

BCD tables only load in the browser

See also