Date.prototype.toISOString()

The toISOString() method of {{jsxref("Date")}} instances returns a string representing this date in the date time string format, a simplified format based on ISO 8601, which is always 24 or 27 characters long (YYYY-MM-DDTHH:mm:ss.sssZ or ±YYYYYY-MM-DDTHH:mm:ss.sssZ, respectively). The timezone is always UTC, as denoted by the suffix Z.

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

```js interactive-example const event = new Date("05 October 2011 14:48 UTC"); console.log(event.toString()); // Expected output: "Wed Oct 05 2011 16:48:00 GMT+0200 (CEST)" // Note: your timezone may vary

console.log(event.toISOString()); // Expected output: "2011-10-05T14:48:00.000Z"

## Syntax

```js-nolint
toISOString()

Parameters#

None.

Return value#

A string representing the given date in the date time string format according to universal time. It's the same format as the one required to be recognized by {{jsxref("Date.parse()")}}.

Exceptions#

• {{jsxref("RangeError")}}
• : Thrown if the date is invalid or if it corresponds to a year that cannot be represented in the date string format.

Examples#

Using toISOString()#

const d = new Date(0);

console.log(d.toISOString()); // "1970-01-01T00:00:00.000Z"

Specifications#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• {{jsxref("Date.prototype.toLocaleDateString()")}}
• {{jsxref("Date.prototype.toString()")}}
• {{jsxref("Date.prototype.toUTCString()")}}