Intl.Locale.prototype.getTimeZones()

None.

An array of strings representing supported time zones for the associated Locale, where each value is an IANA time zone canonical name, sorted in alphabetical order. If the locale identifier does not contain a region subtag, the returned value is undefined.

Note that while the IANA database changes from time to time, the Unicode CLDR database (which browsers use) keeps old time zone names for stability purposes. For example, here are a few notable name changes:

Some browsers (Firefox) override these legacy names, while others don't (Safari and Chrome). For more information, check the CLDR database. (IANA names are marked with "_iana", if different.) There is an effort in TC39 to properly handle these canonical identifiers, which also contains links to related CLDR issues.

List supported time zones for a given Locale.

const arEG = new Intl.Locale("ar-EG");
console.log(arEG.getTimeZones()); // ["Africa/Cairo"]

const jaJP = new Intl.Locale("ja-JP");
console.log(jaJP.getTimeZones()); // ["Asia/Tokyo"]

const ar = new Intl.Locale("ar");
console.log(ar.getTimeZones()); // undefined

• Intl.Locale
• IANA time zone database on Wikipedia