Date.prototype.toLocaleString() - JavaScript

__defineGetter__() Deprecated
__defineSetter__() Deprecated
__lookupGetter__() Deprecated
__lookupSetter__() Deprecated
toLocaleString()
__proto__ Deprecated
Intl.DateTimeFormat API support, this method delegates to Intl.DateTimeFormat.

Every time toLocaleString is called, it has to perform a search in a big database of localization strings, which is potentially inefficient. When the method is called many times with the same arguments, it is better to create a format() method, because a DateTimeFormat object remembers the arguments passed to it and may decide to cache a slice of the database, so future format calls can search for localization strings within a more constrained context.

Try it

const event = new Date(Date.UTC(2012, 11, 20, 3, 0, 0)); / British English uses day-month-year order and 24-hour time without AM/PM console.log(event.toLocaleString("en-GB", { timeZone: "UTC" })); / Expected output: "20/12/2012, 03:00:00" / Korean uses year-month-day order and 12-hour time with AM/PM console.log(event.toLocaleString("ko-KR", { timeZone: "UTC" })); / Expected output: "2012. 12. 20. 오전 3:00:00"

Syntax

toLocaleString()
toLocaleString(locales)
toLocaleString(locales, options)

Parameters

The locales and options parameters customize the behavior of the function and let applications specify the language whose formatting conventions should be used.

In implementations that support the Intl.DateTimeFormat() constructor's parameters. Implementations without Intl.DateTimeFormat support are asked to ignore both parameters, making the locale used and the form of the string returned entirely implementation-dependent.

locales Optional

A string with a BCP 47 language tag, or an array of such strings. Corresponds to the locales parameter of the Intl.DateTimeFormat() constructor.

In implementations without Intl.DateTimeFormat support, this parameter is ignored and the host's locale is usually used.

options Optional

An object adjusting the output format. Corresponds to the options parameter of the Intl.DateTimeFormat() constructor. If weekday, year, month, day, dayPeriod, hour, minute, second, and fractionalSecondDigits are all undefined, then year, month, day, hour, minute, second will be set to "numeric".

In implementations without Intl.DateTimeFormat support, this parameter is ignored.

See the Intl.DateTimeFormat() constructor for details on these parameters and how to use them.

Return value

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

In implementations with Intl.DateTimeFormat, this is equivalent to new Intl.DateTimeFormat(locales, options).format(date).

Note: Most of the time, the formatting returned by toLocaleString() is consistent. However, the output may vary between implementations, even within the same locale — output variations are by design and allowed by the specification. It may also not be what you expect. For example, the string may use non-breaking spaces or be surrounded by bidirectional control characters. You should not compare the results of toLocaleString() to hardcoded constants.

Examples

Using toLocaleString()

Basic use of this method without specifying a locale returns a formatted string in the default locale and with default options.

js
const 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 parameters

The locales and options parameters may not be supported in all implementations, because support for the internationalization API is optional, and some systems may not have the necessary data. For implementations without internationalization support, toLocaleString() always uses the system's locale, which may not be what you want. Because any implementation that supports the locales and options parameters must support the Intl API, you can check the existence of the latter for support:

js
function toLocaleStringSupportsLocales() { return ( typeof Intl === "object" && !!Intl && typeof Intl.DateTimeFormat === "function" ); }

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:

js
const 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 Eastern Arabic numerals 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 parameter:

js
const date = new Date(Date.UTC(2012, 11, 20, 3, 0, 0)); / Request a weekday along with a long date const 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"

Specifications

Specification
ECMAScript® 2026 Internationalization API Specification # sup-date.prototype.tolocalestring

Browser compatibility

See also

Intl.DateTimeFormat

Date.prototype.toLocaleDateString()

Date.prototype.toLocaleTimeString()

Date.prototype.toString()

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