Date.prototype.setSeconds()

The setSeconds() method of {{jsxref("Date")}} instances changes the seconds and/or milliseconds for this date according to local time.

{{InteractiveExample("JavaScript Demo: Date.prototype.setSeconds()")}}

```js interactive-example const event = new Date("August 19, 1975 23:15:30");

event.setSeconds(42);

console.log(event.getSeconds()); // Expected output: 42

console.log(event); // Expected output: "Sat Apr 19 1975 23:15:42 GMT+0100 (CET)" // Note: your timezone may vary

## Syntax

```js-nolint
setSeconds(secondsValue)
setSeconds(secondsValue, msValue)

Parameters#

• secondsValue
• : An integer between 0 and 59 representing the seconds.
• msValue {{optional_inline}}
• : An integer between 0 and 999 representing the milliseconds.

Return value#

Changes the {{jsxref("Date")}} object in place, and returns its new timestamp. If a parameter is NaN (or other values that get coerced to NaN, such as undefined), the date is set to Invalid Date and NaN is returned.

Description#

If you do not specify the msValue parameter, the value returned from the {{jsxref("Date/getMilliseconds", "getMilliseconds()")}} method is used.

If a parameter you specify is outside of the expected range, setSeconds() attempts to update the date information in the {{jsxref("Date")}} object accordingly. For example, if you use 100 for secondsValue, the minutes stored in the {{jsxref("Date")}} object will be incremented by 1, and 40 will be used for seconds.

Because setSeconds() operates on the local time, crossing a Daylight Saving Time (DST) boundary may result in a different elapsed time than expected. For example, if setting the seconds crosses a spring-forward transition (losing an hour), the difference in timestamps between the new and old date is one hour less than the nominal time difference. Conversely, crossing a fall-back transition (gaining an hour) result in an extra hour. If you need to adjust the date by a fixed amount of time, consider using {{jsxref("Date/setUTCSeconds", "setUTCSeconds()")}} or {{jsxref("Date/setTime", "setTime()")}}.

If the new local time falls within an offset transition, the exact time is derived using the same behavior as Temporal's disambiguation: "compatible" option. That is, if the local time corresponds to two instants, the earlier one is chosen; if the local time does not exist (there is a gap), we go forward by the gap duration.

Examples#

Using setSeconds()#

const theBigDay = new Date();
theBigDay.setSeconds(30);

Specifications#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• {{jsxref("Date.prototype.getSeconds()")}}
• {{jsxref("Date.prototype.setUTCSeconds()")}}