Temporal.PlainYearMonth.prototype.subtract()

The subtract() method of {{jsxref("Temporal.PlainYearMonth")}} instances returns a new Temporal.PlainYearMonth object representing this year-month moved backward by a given duration (in a form convertible by {{jsxref("Temporal/Duration/from", "Temporal.Duration.from()")}}).

If you want to subtract two year-months and get a duration, use {{jsxref("Temporal/PlainYearMonth/since", "since()")}} or {{jsxref("Temporal/PlainYearMonth/until", "until()")}} instead.

Syntax#

subtract(duration)
subtract(duration, options)

Parameters#

• duration
• : A string, an object, or a {{jsxref("Temporal.Duration")}} instance representing a duration to subtract from this year-month. 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.PlainYearMonth object representing the year-month specified by the original PlainYearMonth, minus 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#

Subtracting a duration is equivalent to adding its negation, so all the same considerations apply. Subtracting a positive duration starts from the end of the year-month and moves backward, so any increment smaller than the month's length is ignored.

Examples#

Subtracting a duration#

const start = Temporal.PlainYearMonth.from("2022-01");
const end = start.subtract({ years: 1, months: 2, weeks: 3, days: 4 });
console.log(end.toString()); // 2020-11

For more examples, see {{jsxref("Temporal/PlainYearMonth/add", "add()")}}.

Specifications#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• {{jsxref("Temporal.PlainYearMonth")}}
• {{jsxref("Temporal.Duration")}}
• {{jsxref("Temporal/PlainYearMonth/add", "Temporal.PlainYearMonth.prototype.add()")}}
• {{jsxref("Temporal/PlainYearMonth/since", "Temporal.PlainYearMonth.prototype.since()")}}
• {{jsxref("Temporal/PlainYearMonth/until", "Temporal.PlainYearMonth.prototype.until()")}}