Date.prototype.toISOString()

The toISOString() method returns a string in simplified extended ISO format (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 zero UTC offset, as denoted by the suffix "Z".

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

Syntax

dateObj.toISOString()

Return value

A string representing the given date in the ISO 8601 format according to universal time.

Polyfill

This method was standardized in ECMA-262 5th edition. Engines which have not been updated to support this method can work around the absence of this method using the following shim:

if (!Date.prototype.toISOString) {
  (function() {

    function pad(number) {
      if (number < 10) {
        return '0' + number;
      }
      return number;
    }

    Date.prototype.toISOString = function() {
      return this.getUTCFullYear() +
        '-' + pad(this.getUTCMonth() + 1) +
        '-' + pad(this.getUTCDate()) +
        'T' + pad(this.getUTCHours()) +
        ':' + pad(this.getUTCMinutes()) +
        ':' + pad(this.getUTCSeconds()) +
        '.' + (this.getUTCMilliseconds() / 1000).toFixed(3).slice(2, 5) +
        'Z';
    };

  })();
}

Examples

Using toISOString()

let today = new Date('05 October 2011 14:48 UTC')

console.log(today.toISOString())  // Returns 2011-10-05T14:48:00.000Z

The above example uses parsing of a non–standard string value that may not be correctly parsed in non–Mozilla browsers.

Specifications

Browser compatibility

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

See also

• Date.prototype.toLocaleDateString()
• Date.prototype.toTimeString()
• Date.prototype.toUTCString()