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Intl.relativeTimeFormat.RelativeTimeFormat

The Intl.RelativeTimeFormat() constructor creates Intl.RelativeTimeFormat objects.

Syntax

new Intl.RelativeTimeFormat([locales[, options]]) 

Parameters

locales

Optional. A string with a BCP 47 language tag, or an array of such strings. For the general form and interpretation of the locales argument, see the Intl page.

options
Optional. An object with some or all of the following properties:
  • localeMatcher
    The locale matching algorithm to use. Possible values are "lookup" and "best fit"; the default is "best fit". For information about this option, see Intl.
  • numeric
    The format of output message. Possible values are:
    • "always" (default, e.g., 1 day ago),
    • or "auto" (e.g., yesterday). The "auto" value allows to not always have to use numeric values in the output.
  • style
    The length of the internationalized message. Possible values are:
    • "long" (default, e.g., in 1 month)
    • "short" (e.g., in 1 mo.),
    • or "narrow" (e.g., in 1 mo.). The narrow style could be similar to the short style for some locales.

Examples

Basic format usage

The following example shows how to create a relative time formatter using the English language.

// Create a relative time formatter in your locale
// with default values explicitly passed in.
const rtf = new Intl.RelativeTimeFormat("en", {
    localeMatcher: "best fit", // other values: "lookup"
    numeric: "always", // other values: "auto"
    style: "long", // other values: "short" or "narrow"
});

// Format relative time using negative value (-1).
rtf.format(-1, "day");
// > "1 day ago"

// Format relative time using positive  value (1).
rtf.format(1, "day");
// > "in 1 day"

Using the auto option

If numeric:auto option is passed, it will produce the string yesterday or tomorrow instead of 1 day ago or in 1 day. This allows to not always have to use numeric values in the output.

// Create a relative time formatter in your locale
// with numeric: "auto" option value passed in.
const rtf = new Intl.RelativeTimeFormat("en", { numeric: "auto" });

// Format relative time using negative value (-1).
rtf.format(-1, "day");
// > "yesterday"

// Format relative time using positive day unit (1).
rtf.format(1, "day");
// > "tomorrow"

Specifications

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
RelativeTimeFormat() constructor 71 79 65 No 58 14
Mobile
Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
RelativeTimeFormat() constructor 71 71 65 50 14 10.0
Server
Node.js
RelativeTimeFormat() constructor 13.0.0
13.0.0
12.0.0
Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the RelativeTimeFormat instance silently falls back to en-US. To make full ICU (locale) data available for versions prior to 13, see Node.js documentation on the --with-intl option and how to provide the data.

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://wiki.developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/RelativeTimeFormat/RelativeTimeFormat