Internationalization

Table of Contents

• Usage

• Adding New Language

Usage

There are just a few functions that support I18n:

• format
• formatDistance
• formatDistanceStrict
• formatRelative

To use a locale, you need to require it and then pass as an option to a function:

```js import { formatDistance } from 'date-fns' // Require Esperanto locale import { eo } from 'date-fns/locale'

const result = formatDistance( new Date(2016, 7, 1), new Date(2015, 0, 1), {locale: eo} // Pass the locale as an option ) //=> 'pli ol 1 jaro' ```

It might seem complicated to require and pass locales as options, but unlike Moment.js which bloats your build with all the locales by default date-fns forces developer to manually require locales when needed. To make API simple, we encourage you to write tiny wrappers and use those instead of original functions:

```js // app/_lib/format.js

import { format } from 'date-fns' import { enGB, eo, ru } from 'date-fns/locale'

const locales = {enGB, eo, ru}

// by providing a default string of 'PP' or any of its variants for formatStr // it will format dates in whichever way is appropriate to the locale export default function (date, formatStr = 'PP') { return format(date, formatStr, { locale: locales[window.localeId] // or global.localeId }) }

// Later:

import format from 'app/_lib/format'

window.localeId = 'enGB' format(friday13, 'EEEE d') //=> 'Friday 13'

window.localeId = 'eo' format(friday13, 'EEEE d') //=> 'vendredo 13'

// If the format string is omitted, it will take the default for the locale. window.localeId = 'enGB' format(friday13) //=> Jul 13, 2019

window.localeId = 'eo' format(friday13) //=> 2019-jul-13

```

Adding New Language

At the moment there is no definitive guide, so if you feel brave enough, use this quick guide:

• First of all, create an issue so you won't overlap with others.
• A detailed explanation of how to add a new locale.
• Use English locale as the basis and then incrementally adjust the tests and the code.
• Directions on adding a locale with the same language as another locale.
• If you have questions or need guidance, leave a comment in the issue.

Thank you for your support!