Temporal.PlainTime.prototype.add()

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 add() method of Temporal.PlainTime instances returns a new Temporal.PlainTime object representing this time moved forward by a given duration (in a form convertible by Temporal.Duration.from()), wrapping around the clock if necessary.

Syntax

add(duration)

Parameters

duration: A string, an object, or a Temporal.Duration instance representing a duration to add to this time. It is converted to a Temporal.Duration object using the same algorithm as Temporal.Duration.from().

Return value

A new Temporal.PlainTime object representing the time specified by the original PlainTime, plus the duration. Any units above hours are ignored, and if the time goes past midnight, it wraps around to the next day.

Adding a duration is equivalent to subtracting its negation.

Examples

Adding a duration

const start = Temporal.PlainTime.from("12:34:56");
const end = start.add({ hours: 1, minutes: 30 });
console.log(end.toString()); // 14:04:56

const end2 = start.add({ hours: -1, minutes: -30 });
console.log(end2.toString()); // 11:04:56

const distance = Temporal.PlainTime.from("00:00:00").until("01:23:45"); // 1h 23m 45s
const end3 = start.add(distance);
console.log(end3.toString()); // 13:58:41

Time wrapping

If the time goes past midnight, it wraps around to the next day:

const start = Temporal.PlainTime.from("12:34:56");
const end = start.add({ hours: 12 });
console.log(end.toString()); // 00:34:56

Specifications

Specification
Temporal proposal # sec-temporal.plaintime.prototype.add

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
`add`	No	No	No	No	preview	No	No	No	No	No	No	1.40	No