Temporal.ZonedDateTime.prototype.epochMilliseconds

The epochMilliseconds accessor property of {{jsxref("Temporal.ZonedDateTime")}} instances returns an integer representing the number of milliseconds elapsed since the Unix epoch (midnight at the beginning of January 1, 1970, UTC) to this instant. It is equivalent to dividing epochNanoseconds by 1e6 and flooring the result.

The set accessor of epochMilliseconds is undefined. You cannot change this property directly. To create a new Temporal.ZonedDateTime object with the desired new epochMilliseconds value, see below.

Examples#

Using epochMilliseconds#

const zdt = Temporal.ZonedDateTime.from("2021-08-01T12:34:56.789Z[UTC]");
console.log(zdt.epochMilliseconds); // 1627821296789

const zdt2 = Temporal.ZonedDateTime.from("1969-08-01T12:34:56.789Z[UTC]");
console.log(zdt2.epochMilliseconds); // -13173903211

Creating a ZonedDateTime object from an epochMilliseconds value#

You can create a Temporal.ZonedDateTime object from an epochMilliseconds value by first constructing a Temporal.Instant object using {{jsxref("Temporal/Instant/fromEpochMilliseconds", "Temporal.Instant.fromEpochMilliseconds()")}}, and then converting it to a Temporal.ZonedDateTime object using {{jsxref("Temporal/Instant/toZonedDateTimeISO", "Temporal.Instant.prototype.toZonedDateTimeISO()")}}:

const epochMilliseconds = 1627821296789;
const instant = Temporal.Instant.fromEpochMilliseconds(epochMilliseconds);
const zdt = instant.toZonedDateTimeISO("UTC");
console.log(zdt.toString()); // 2021-08-01T12:34:56.789+00:00[UTC]

Alternatively, use the {{jsxref("Temporal/ZonedDateTime/ZonedDateTime", "Temporal.ZonedDateTime()")}} constructor, but convert the milliseconds to nanoseconds first:

const epochMilliseconds = 1627821296789;
const epochNanoseconds = BigInt(epochMilliseconds) * 1_000_000n;
const zdt = new Temporal.ZonedDateTime(epochNanoseconds, "UTC");
console.log(zdt.toString()); // 2021-08-01T12:34:56.789+00:00[UTC]

Specifications#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• {{jsxref("Temporal.ZonedDateTime")}}
• {{jsxref("Temporal/ZonedDateTime/epochNanoseconds", "Temporal.ZonedDateTime.prototype.epochNanoseconds")}}