How can I get the timezone name in JavaScript?

Question

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.

Retrieve timezone by name (i.e. "America/New York")

moment.tz.guess();

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!

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

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