Temporal.PlainDateTime.prototype.add()

The add() method of {{jsxref("Temporal.PlainDateTime")}} instances returns a new Temporal.PlainDateTime object representing this date-time moved forward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).

Syntax#

add(duration)
add(duration, options)

Parameters#

• duration
• : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing a duration to add to this date-time. It is converted to a Temporal.Duration object using the same algorithm as {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}.
• options {{optional_inline}}
• : An object containing the following property:
  • overflow {{optional_inline}}
  • : A string specifying the behavior when a date component is out of range. Possible values are:
    • "constrain" (default)
    • : The date component is clamped to the valid range.
    • "reject"
    • : A {{jsxref("RangeError")}} is thrown if the date component is out of range.

Return value#

A new Temporal.PlainDateTime object representing the date-time specified by the original PlainDateTime, plus the duration.

Exceptions#

• {{jsxref("RangeError")}}
• : Thrown if the result is not in the representable range, which is ±(10⁸ + 1) days, or about ±273,972.6 years, from the Unix epoch.

Description#

For how calendar durations are added, see {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}.

Adding a duration is equivalent to subtracting its negation.

Examples#

Adding a duration#

const start = Temporal.PlainDateTime.from("2021-01-01T12:34:56");
const end = start.add({
  years: 1,
  months: 2,
  weeks: 3,
  days: 4,
  hours: 5,
  minutes: 6,
  seconds: 7,
  milliseconds: 8,
});
console.log(end.toString()); // 2022-03-26T17:41:03.008

For more examples, especially with how different calendars and the overflow option interact with calendar durations, see {{jsxref("Temporal/PlainDate/add", "Temporal.PlainDate.prototype.add()")}}.

Specifications#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• {{jsxref("Temporal.PlainDateTime")}}
• {{jsxref("Temporal.Duration")}}
• {{jsxref("Temporal/PlainDateTime/subtract", "Temporal.PlainDateTime.prototype.subtract()")}}