Date.prototype.toLocaleTimeString() - JavaScript 编辑

The toLocaleTimeString() method returns a string with a language sensitive representation of the time portion 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.

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

Syntax

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

Parameters

The locales and options arguments customize the behavior of the function and let applications specify the language whose formatting conventions should be used. In implementations, which ignore the locales and options arguments, the locale used and the form of the string returned are entirely implementation dependent.

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

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

Return value

A string representing the time portion of the given Date instance according to language-specific conventions.

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.

Examples

Using toLocaleTimeString()

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));

// toLocaleTimeString() without arguments depends on the implementation,
// the default locale, and the default time zone
console.log(date.toLocaleTimeString());
// → "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 toLocaleTimeStringSupportsLocales() {
  try {
    new Date().toLocaleTimeString('i');
  } catch (e) {
    return e.name === 'RangeError';
  }
  return false;
}

Using locales

This example shows some of the variations in localized 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 12-hour time with AM/PM
console.log(date.toLocaleTimeString('en-US'));
// → "7:00:00 PM"

// British English uses 24-hour time without AM/PM
console.log(date.toLocaleTimeString('en-GB'));
// → "03:00:00"

// Korean uses 12-hour time with AM/PM
console.log(date.toLocaleTimeString('ko-KR'));
// → "오후 12:00:00"

// Arabic in most Arabic speaking countries uses real Arabic digits
console.log(date.toLocaleTimeString('ar-EG'));
// → "٧:٠٠:٠٠ م"

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

Using options

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

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

// an application may want to use UTC and make that visible
var options = { timeZone: 'UTC', timeZoneName: 'short' };
console.log(date.toLocaleTimeString('en-US', options));
// → "3:00:00 AM GMT"

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

// show only hours and minutes, use options with the default locale - use an empty array
console.log(date.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' }));
// → "20:01"

Specifications

Specification
ECMAScript (ECMA-262) The definition of 'Date.prototype.toLocaleTimeString' in that specification.
ECMAScript Internationalization API (ECMA-402) The definition of 'Date.prototype.toLocaleTimeString' in that specification.

Browser compatibility

BCD tables only load in the browser

See also

• Intl.DateTimeFormat
• Date.prototype.toLocaleDateString()
• Date.prototype.toLocaleString()
• Date.prototype.toTimeString()
• Date.prototype.toString()