The Intl.Locale.prototype.calendar property is an accessor property which returns the type of calendar used in the Locale.


The calendar property returns the part of the Locale that indicates the Locale's calendar era. While most of the world uses the Gregorian calendar, there are several regional calendar eras used around the world. The following table shows all the valid Unicode calendar key strings, along with a description of the calendar era they represent.

Unicode calendar keys

Unicode calendar keys
Calendar key (name) Description
buddhist Thai Buddhist calendar
chinese Traditional Chinese calendar
coptic Coptic calendar
dangi Traditional Korean calendar
ethioaa Ethiopic calendar, Amete Alem (epoch approx. 5493 B.C.E)
ethiopic Ethiopic calendar, Amete Mihret (epoch approx, 8 C.E.)
gregory Gregorian calendar
hebrew Traditional Hebrew calendar
indian Indian calendar
islamic Islamic calendar
islamic-umalqura Islamic calendar, Umm al-Qura
islamic-tbla Islamic calendar, tabular (intercalary years [2,5,7,10,13,16,18,21,24,26,29] - astronomical epoch)
islamic-civil Islamic calendar, tabular (intercalary years [2,5,7,10,13,16,18,21,24,26,29] - civil epoch)
islamic-rgsa Islamic calendar, Saudi Arabia sighting
iso8601 ISO calendar (Gregorian calendar using the ISO 8601 calendar week rules)
japanese Japanese Imperial calendar
persian Persian calendar
roc Republic of China calendar
The islamicc calendar key has been deprecated. Please use islamic-civil.


Civil (algorithmic) Arabic calendar


Adding a calendar in the Locale string

Calendar eras fall under the category of locale key "extension keys". These keys add additional data about the locale, and are added to locale identifiers by using the -u extension. Thus, the calendar era type can be added to the inital locale identifier string that is passed into the Intl.Locale constructor. To add the calendar type, first add the -u extension to the string. Next, add the -ca extension to indicate that you are adding a calendar type. Finally, add the calendar era to the string.

let frBuddhist = new Intl.Locale("fr-FR-u-ca-buddhist");
console.log(frBuddhist.calendar); // Prints "buddhist"

Adding a calendar with a configuration object

The Intl.Locale constructor has an optional configuration object argument, which can contain any of several extension types, including calendars. Set the calendar property of the configuration object to your desired calendar era, and then pass it into the constructor.

let frBuddhist = new Intl.Locale("fr-FR", {calendar: "buddhist"});
console.log(frBuddhist.calendar); // Prints "buddhist"


Browser compatibilityUpdate compatibility data on GitHub

Chrome Edge Firefox Internet Explorer Opera Safari
calendar 74 79 75 No 62 14
Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
calendar 74 74 No 53 14 11.0
calendar 12.0.0
Before version 13.0.0, only the locale data for en-US is available by default. See the Locale() constructor for more details.

See also

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