Temporal.ZonedDateTime.prototype.offsetNanoseconds

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 offsetNanoseconds accessor property of Temporal.ZonedDateTime instances returns an integer representing the offset used to interpret the internal instant, as a number of nanoseconds (positive or negative). The value is a safe integer because it's less than a day, which is 8.64e15 nanoseconds.

The set accessor of offsetNanoseconds is undefined. You cannot change this property directly. Change offset to change this property too.

Examples

Using offsetNanoseconds

js
const dt = Temporal.ZonedDateTime.from(
  "2021-07-01T12:00:00-07:00[America/Los_Angeles]",
);
console.log(dt.offsetNanoseconds); // -25200000000000

const dt2 = Temporal.ZonedDateTime.from(
  "2021-07-01T12:00:00+08:00[Asia/Shanghai]",
);
console.log(dt2.offsetNanoseconds); // 28800000000000

const dt3 = Temporal.ZonedDateTime.from(
  "1900-01-01T00:00:00+00:09:21[Europe/Paris]",
);
console.log(dt3.offsetNanoseconds); // 561000000000

Here's one way to get a ZonedDateTime representing the same wall-clock time in UTC:

js
const dt = Temporal.ZonedDateTime.from(
  "2021-07-01T12:00:00-07:00[America/Los_Angeles]",
);
const dtInUTC = dt.add({ nanoseconds: dt.offsetNanoseconds });
console.log(dtInUTC.withTimeZone("UTC").toString()); // "2021-07-01T12:00:00+00:00[UTC]"

Here's a better way to get the same result:

js
const dt = Temporal.ZonedDateTime.from(
  "2021-07-01T12:00:00-07:00[America/Los_Angeles]",
);
const dtInUTC = dt.toPlainDateTime().toZonedDateTime("UTC");
console.log(dtInUTC.toString()); // "2021-07-01T12:00:00+00:00[UTC]"

Specifications

Specification
Temporal proposal
# sec-get-temporal.zoneddatetime.prototype.offsetnanoseconds

Browser compatibility

BCD tables only load in the browser

See also