Internationalization (i18n)

Day.js supports internationalization through locale files that are loaded on demand.

Changing Locale Globally

import 'dayjs/locale/tr'; // import Turkish locale
dayjs.locale('tr');

dayjs('2024-06-15').format('dddd, MMMM D, YYYY');
// "Cumartesi, Haziran 15, 2024"

Changing Locale Per Instance

import 'dayjs/locale/de';
import 'dayjs/locale/fr';

dayjs('2024-06-15').locale('de').format('dddd, MMMM D');
// "Samstag, Juni 15"

dayjs('2024-06-15').locale('fr').format('dddd, MMMM D');
// "samedi, juin 15"

Available Locales

Day.js supports 100+ locales including:

Locale	Code	Example Output
English	`en`	Saturday, June 15
Turkish	`tr`	Cumartesi, Haziran 15
German	`de`	Samstag, Juni 15
French	`fr`	samedi, juin 15
Spanish	`es`	sábado, junio 15
Japanese	`ja`	土曜日, 6月 15
Chinese (Simplified)	`zh-cn`	星期六, 六月 15
Arabic	`ar`	السبت, يونيو ١٥
Russian	`ru`	суббота, июня 15

Locale Data

import 'dayjs/locale/en';

const localeData = dayjs.localeData();
localeData.months();
// ["January", "February", ..., "December"]

localeData.monthsShort();
// ["Jan", "Feb", ..., "Dec"]

localeData.weekdays();
// ["Sunday", "Monday", ..., "Saturday"]

localeData.weekdaysMin();
// ["Su", "Mo", ..., "Sa"]

localeData.weekdaysShort();
// ["Sun", "Mon", ..., "Sat"]

Custom Locale

const customLocale = {
  name: 'custom',
  weekdays: 'Sunday_Monday_Tuesday_Wednesday_Thursday_Friday_Saturday'.split('_'),
  months: 'January_February_March_April_May_June_July_August_September_October_November_December'.split('_'),
  relativeTime: {
    future: 'in %s',
    past: '%s ago',
    s: 'a few seconds',
    m: 'a minute',
    mm: '%d minutes',
    h: 'an hour',
    hh: '%d hours',
    d: 'a day',
    dd: '%d days',
    M: 'a month',
    MM: '%d months',
    y: 'a year',
    yy: '%d years',
  },
};
dayjs.locale('custom', customLocale);