This feature is not Baseline because it does not work in some of the most widely-used browsers.
The offset accessor property of Temporal.ZonedDateTime instances returns a string representing the offset used to interpret the internal instant, in the form ±HH:mm (or ±HH:mm:ss.sssssssss with as much subminute precision as necessary). This offset is guaranteed to be valid for the given instant and time zone at construction time.
The set accessor of offset is undefined. You cannot change this property directly. Use the with() method to create a new Temporal.ZonedDateTime object with the desired new value (usually also changing the date/time), or use the withTimeZone() method to create a new Temporal.ZonedDateTime object in another time zone.
const dt = Temporal.ZonedDateTime.from(
"2021-07-01T12:00:00-07:00[America/Los_Angeles]",
);
console.log(dt.offset); // "-07:00"
const dt2 = Temporal.ZonedDateTime.from("2021-07-01T12:00:00-07[-07]");
console.log(dt2.offset); // "-07:00"
const dt3 = Temporal.ZonedDateTime.from(
"1900-01-01T00:00:00+00:09:21[Europe/Paris]",
);
console.log(dt3.offset); // "+00:09:21"
const dt4 = Temporal.ZonedDateTime.from("2021-07-01T12:00:00Z[Asia/Shanghai]");
console.log(dt4.offset); // "+08:00"
If the local time happens to have two valid offsets, such as within a DST transition, you can change the offset without changing anything else:
const zdt = Temporal.ZonedDateTime.from(
"2024-11-03T01:05:00-04:00[America/New_York]",
);
const newZDT = zdt.with({ offset: "-05:00" });
console.log(newZDT.toString()); // "2024-11-03T01:05:00-05:00[America/New_York]"
| Desktop | Mobile | Server | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Opera | Safari | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | WebView Android | WebView on iOS | Bun | Deno | Node.js | |
offset |
144 | 144 | 139 | No | No | 144 | 139 | No | No | No | 144 | No | ? | 1.40 | No |
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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime/offset