Date.prototype.toLocaleString()

The toLocaleString() method returns a string with a language sensitive representation of this date. The new locales and options arguments let applications specify the language whose formatting conventions should be used and customize the behavior of the function. In older implementations, which ignore the locales and options arguments, the locale used and the form of the string returned are entirely implementation dependent.

Syntax

JavaScript
<var>dateObj</var>.toLocaleString([<var>locales</var>[, <var>options</var>]])

Parameters

Check the Browser compatibility section to see which browsers support the locales and options arguments, and the Example: Checking for support for locales and options arguments for feature detection.

locales

Optional. A string with a BCP 47 language tag, or an array of such strings. For the general form and interpretation of the locales argument, see the Intl page. The following Unicode extension keys are allowed:

nu
Numbering system. Possible values include: "arab", "arabext", "bali", "beng", "deva", "fullwide", "gujr", "guru", "hanidec", "khmr", "knda", "laoo", "latn", "limb", "mlym", "mong", "mymr", "orya", "tamldec", "telu", "thai", "tibt".
ca
Calendar. Possible values include: "buddhist", "chinese", "coptic", "ethioaa", "ethiopic", "gregory", "hebrew", "indian", "islamic", "islamicc", "iso8601", "japanese", "persian", "roc".
options

Optional. An object with some or all of the following properties:

localeMatcher
The locale matching algorithm to use. Possible values are "lookup" and "best fit"; the default is "best fit". For information about this option, see the Intl page.
timeZone
The time zone to use. The only value implementations must recognize is "UTC"; the default is the runtime's default time zone. Implementations may also recognize the time zone names of the IANA time zone database, such as "Asia/Shanghai", "Asia/Kolkata", "America/New_York".
hour12
Whether to use 12-hour time (as opposed to 24-hour time). Possible values are true and false; the default is locale dependent.
formatMatcher
The format matching algorithm to use. Possible values are "basic" and "best fit"; the default is "best fit". See the following paragraphs for information about the use of this property.

The following properties describe the date-time components to use in formatted output, and their desired representations. Implementations are required to support at least the following subsets:

  • weekday, year, month, day, hour, minute, second
  • weekday, year, month, day
  • year, month, day
  • year, month
  • month, day
  • hour, minute, second
  • hour, minute

Implementations may support other subsets, and requests will be negotiated against all available subset-representation combinations to find the best match. Two algorithms are available for this negotiation and selected by the formatMatcher property: A fully specified "basic" algorithm and an implementation dependent "best fit" algorithm.

weekday
The representation of the weekday. Possible values are "narrow", "short", "long".
era
The representation of the era. Possible values are "narrow", "short", "long".
year
The representation of the year. Possible values are "numeric", "2-digit".
month
The representation of the month. Possible values are "numeric", "2-digit", "narrow", "short", "long".
day
The representation of the day. Possible values are "numeric", "2-digit".
hour
The representation of the hour. Possible values are "numeric", "2-digit".
minute
The representation of the minute. Possible values are "numeric", "2-digit".
second
The representation of the second. Possible values are "numeric", "2-digit".
timeZoneName
The representation of the time zone name. Possible values are "short", "long".

The default value for each date-time component property is undefined, but if the weekday, year, month, day, hour, minute, second properties are all undefined, then year, month, day, hour, minute, and second are assumed to be "numeric".

Return value

A string representing the given date according to language-specific conventions.

Examples

Using toLocaleString()

In basic use without specifying a locale, a formatted string in the default locale and with default options is returned.

JavaScript
var date = new Date(Date.UTC(2012, 11, 12, 3, 0, 0));

// toLocaleString() without arguments depends on the implementation,
// the default locale, and the default time zone
console.log(date.toLocaleString());
// → "12/11/2012, 7:00:00 PM" if run in en-US locale with time zone America/Los_Angeles

Checking for support for locales and options arguments

The locales and options arguments are not supported in all browsers yet. To check whether an implementation supports them already, you can use the requirement that illegal language tags are rejected with a RangeError exception:

JavaScript
function toLocaleStringSupportsLocales() {
  try {
    new Date().toLocaleString('i');
  } catch (e) {
    return e​.name === 'RangeError';
  }
  return false;
}

Using locales

This example shows some of the variations in localized date and time formats. In order to get the format of the language used in the user interface of your application, make sure to specify that language (and possibly some fallback languages) using the locales argument:

JavaScript
var date = new Date(Date.UTC(2012, 11, 20, 3, 0, 0));

// formats below assume the local time zone of the locale;
// America/Los_Angeles for the US

// US English uses month-day-year order and 12-hour time with AM/PM
console.log(date.toLocaleString('en-US'));
// → "12/19/2012, 7:00:00 PM"

// British English uses day-month-year order and 24-hour time without AM/PM
console.log(date.toLocaleString('en-GB'));
// → "20/12/2012 03:00:00"

// Korean uses year-month-day order and 12-hour time with AM/PM
console.log(date.toLocaleString('ko-KR'));
// → "2012. 12. 20. 오후 12:00:00"

// Arabic in most Arabic speaking countries uses real Arabic digits
console.log(date.toLocaleString('ar-EG'));
// → "٢٠‏/١٢‏/٢٠١٢ ٥:٠٠:٠٠ ص"

// for Japanese, applications may want to use the Japanese calendar,
// where 2012 was the year 24 of the Heisei era
console.log(date.toLocaleString('ja-JP-u-ca-japanese'));
// → "24/12/20 12:00:00"

// when requesting a language that may not be supported, such as
// Balinese, include a fallback language, in this case Indonesian
console.log(date.toLocaleString(['ban', 'id']));
// → "20/12/2012 11.00.00"

Using options

The results provided by toLocaleString() can be customized using the options argument:

JavaScript
var date = new Date(Date.UTC(2012, 11, 20, 3, 0, 0));

// request a weekday along with a long date
var options = { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric' };
console.log(date.toLocaleString('de-DE', options));
// → "Donnerstag, 20. Dezember 2012"

// an application may want to use UTC and make that visible
options.timeZone = 'UTC';
options.timeZoneName = 'short';
console.log(date.toLocaleString('en-US', options));
// → "Thursday, December 20, 2012, GMT"

// sometimes even the US needs 24-hour time
console.log(date.toLocaleString('en-US', { hour12: false }));
// → "12/19/2012, 19:00:00"

Performance

When formatting large numbers of dates, it is better to create an Intl.DateTimeFormat object and use the function provided by its format property.

Specifications

Specification Status Comment
ECMAScript 1st Edition (ECMA-262) Standard Initial definition. Implemented in JavaScript 1.0.
ECMAScript 5.1 (ECMA-262)
The definition of 'Date.prototype.toLocaleString' in that specification.
Standard  
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Date.prototype.toLocaleString' in that specification.
Standard  
ECMAScript 2017 Draft (ECMA-262)
The definition of 'Date.prototype.toLocaleString' in that specification.
Draft  
ECMAScript Internationalization API 1.0 (ECMA-402)
The definition of 'Date.prototype.toLocaleString' in that specification.
Standard Defines locales and options arguments.
ECMAScript Internationalization API 2.0 (ECMA-402)
The definition of 'Date.prototype.toLocaleString' in that specification.
Standard  
ECMAScript Internationalization API 4.0 (ECMA-402)
The definition of 'Date.prototype.toLocaleString' in that specification.
Draft  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) (Yes) (Yes) (Yes) (Yes)
locales and options arguments 24 29 (29) 11 15 No support
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)
locales and options arguments No support 26 No support No support No support No support

See also

License

© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/javascript/reference/global_objects/date/tolocalestring

Date Internationalization JavaScript Method Prototype Reference