Temporal.ZonedDateTime.prototype.hoursInDay

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 hoursInDay accessor property of Temporal.ZonedDateTime instances returns a positive integer representing the number of hours in the day of this date in the time zone. It may be more or less than 24 in the case of offset changes such as daylight saving time.

Because ZonedDateTime is the only class that's time zone-aware, and hours in a day can only change by offset changes, all other classes assume 24-hour days.

The set accessor of hoursInDay is undefined. You cannot change this property directly.

Examples

Using hoursInDay

const dt = Temporal.ZonedDateTime.from(
  "2024-03-10T01:58:00-05:00[America/New_York]",
);
console.log(dt.hoursInDay); // 23; this is the day of transition into DST

const dt2 = Temporal.ZonedDateTime.from(
  "2024-11-03T01:58:00-04:00[America/New_York]",
);
console.log(dt2.hoursInDay); // 25; this is the day of transition out of DST

const dt3 = Temporal.ZonedDateTime.from(
  "2024-11-04T01:58:00-05:00[America/New_York]",
);
console.log(dt3.hoursInDay); // 24

Specifications

Specification
Temporal # sec-get-temporal.zoneddatetime.prototype.hoursinday

Browser compatibility

	Desktop					Mobile						Server
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet	WebView Android	Deno	Node.js
`hoursInDay`	No	No	139	No	No	No	139	No	No	No	No	1.40	No

Examples

Using hoursInDay

Specifications

Browser compatibility

See also