Date.prototype.toLocaleString()
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2017.
The toLocaleString()
method of Date
instances returns a string with a language-sensitive representation of this date in the local timezone. In implementations with Intl.DateTimeFormat
API support, this method simply calls 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 Intl.DateTimeFormat
object and use its 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
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
API, these parameters correspond exactly to 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 theIntl.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 theIntl.DateTimeFormat()
constructor. Ifweekday
,year
,month
,day
,dayPeriod
,hour
,minute
,second
, andfractionalSecondDigits
are all undefined, thenyear
,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.
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:
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:
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:
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 Language Specification # sec-date.prototype.tolocalestring |
ECMAScript Internationalization API Specification # sup-date.prototype.tolocalestring |
Browser compatibility
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