Date.prototype.toLocaleString()

El método toLocaleString() devuelve un cadena con la representación al idioma de la fecha especificada. Los nuevos argumentos locales y options permiten a las aplicaciones especificar el idioma cuyas convenciones de formato deben usarse y personalizar el comportamiento de la función. En implementaciones anteriores, ignoran los argumentos de las configuraciones localesoptions , la configuración regional utilizada y la forma de la cadena devuelta dependen completamente de la implementación .

Syntax

dateObj.toLocaleString([locales[, options]])

Parametros

Los argumentos locales y de options  personalizan el comportamiento de la función y permiten que las aplicaciones especifiquen el lenguaje cuyas convenciones de formato deben ser utilizadas. En las implementaciones, que ignoran los argumentos, localesoptions, el locale utilizado y la forma de la cadena devuelta dependen totalmente de la implementación.

Vea el  constructor de Intl.DateTimeFormat() para detalles en esos parametros y como se usan.

El valor por defecto para cada componente date-time es  undefined, pero si las propiedades weekday, year, month, day son todas undefined, entonces year, month, y day son asumidas como "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.

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:

function toLocaleStringSupportsLocales() {
  try {
    new Date().toLocaleString('i');
  } catch (e) {
    return e instanceof 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:

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:

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"

Avoid comparing formatted date values to static values

Most of the time, the formatting returned by toLocaleString() is consistent. However, this might change in the future and isn't guaranteed for all languages — output variations are by design and allowed by the specification. Most notably, the IE and Edge browsers insert bidirectional control characters around dates, so the output text will flow properly when concatenated with other text.

For this reason you cannot expect to be able to compare the results of toLocaleString() to a static value:

"1/1/2019, 01:00:00" === new Date("2019-01-01T01:00:00Z").toLocaleString("en-US");
// true in Firefox and others
// false in IE and Edge

Note: See also this StackOverflow thread for more details and examples.

Performance

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

Specifications

Specification
ECMAScript (ECMA-262)
La definición de 'Date.prototype.toLocaleString' en esta especificación.
ECMAScript Internationalization API (ECMA-402)
La definición de 'Date.prototype.toLocaleString' en esta especificación.

Browser compatibility

BCD tables only load in the browser

See also