How can I get the timezone name in JavaScript?

I know how to get the timezone offset, but what I need is the ability to detect something like "America/New York." Is that even possible from JavaScript or is that something I am going to have to guestimate based on the offset?

The Internationalization API supports getting the user timezone, and is supported in all current browsers.

console.log(Intl.DateTimeFormat().resolvedOptions().timeZone)

Keep in mind that on some older browser versions that support the Internationalization API, the timeZone property is set to undefined rather than the user’s timezone string. As best as I can tell, at the time of writing (July 2017) all current browsers except for IE11 will return the user timezone as a string.

Most upvoted answer is probably the best way to get the timezone, however, Intl.DateTimeFormat().resolvedOptions().timeZone returns IANA timezone name by definition, which is in English.

If you want the timezone's name in current user's language, you can parse it from Date's string representation like so:

function getTimezoneName() {
  const today = new Date();
  const short = today.toLocaleDateString(undefined);
  const full = today.toLocaleDateString(undefined, { timeZoneName: 'long' });

  // Trying to remove date from the string in a locale-agnostic way
  const shortIndex = full.indexOf(short);
  if (shortIndex >= 0) {
    const trimmed = full.substring(0, shortIndex) + full.substring(shortIndex + short.length);
    
    // by this time `trimmed` should be the timezone's name with some punctuation -
    // trim it from both sides
    return trimmed.replace(/^[\s,.\-:;]+|[\s,.\-:;]+$/g, '');

  } else {
    // in some magic case when short representation of date is not present in the long one, just return the long one as a fallback, since it should contain the timezone's name
    return full;
  }
}

console.log(getTimezoneName());

Tested in Chrome and Firefox.

Ofcourse, this will not work as intended in some of the environments. For example, node.js returns a GMT offset (e.g. GMT+07:00) instead of a name. But I think it's still readable as a fallback.

P.S. Won't work in IE11, just as the Intl... solution.

A short possibility for a result in current user's language:

console.log(new Date().toLocaleDateString(undefined, {day:'2-digit',timeZoneName: 'long' }).substring(4));

If you're already using Moment.js you can guess the timezone name:

moment.tz.guess(); // eg. "America/New York"

You can use this script. http://pellepim.bitbucket.org/jstz/

Fork or clone repository here. https://bitbucket.org/pellepim/jstimezonedetect

Once you include the script, you can get the list of timezones in - jstz.olson.timezones variable.

And following code is used to determine client browser's timezone.

var tz = jstz.determine();
tz.name();

Enjoy jstz!

You can simply write your own code by using the mapping table here: http://www.timeanddate.com/time/zones/

or, use moment-timezone library: http://momentjs.com/timezone/docs/

See zone.name; // America/Los_Angeles

or, this library: https://github.com/Canop/tzdetect.js

To detect something like "America/New York.", you can use the new LocalZone() from the Luxon library.

import { LocalZone } from 'luxon';

const zoneName = new LocalZone().name;

This gets the timezone code (e.g., GMT) in older javascript (I'm using google app script with old engine):

function getTimezoneName() {
  return new Date().toString().get(/\((.+)\)/);
}

I'm just putting this here in case someone needs it.

In javascript , the Date.getTimezoneOffset() method returns the time-zone offset from UTC, in minutes, for the current locale.

var x = new Date();
var currentTimeZoneOffsetInHours = x.getTimezoneOffset() / 60;

Moment'timezone will be a useful tool. http://momentjs.com/timezone/

Convert Dates Between Timezones

var newYork    = moment.tz("2014-06-01 12:00", "America/New_York");
var losAngeles = newYork.clone().tz("America/Los_Angeles");
var london     = newYork.clone().tz("Europe/London");

newYork.format();    // 2014-06-01T12:00:00-04:00
losAngeles.format(); // 2014-06-01T09:00:00-07:00
london.format();     // 2014-06-01T17:00:00+01:00