Intl.RelativeTimeFormat() constructor

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

Specification Status Comment
ECMAScript Internationalization API (ECMA-402)
The definition of 'RelativeTimeFormat()' in that specification.
Stage 4

Browser compatibility

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
RelativeTimeFormat() constructorChrome Full support 71Edge Full support 79Firefox Full support 65IE No support NoOpera Full support 58Safari Full support 14WebView Android Full support 71Chrome Android Full support 71Firefox Android Full support 65Opera Android Full support 50Safari iOS Full support 14Samsung Internet Android Full support 10.0nodejs Full support 13.0.0
Full support 13.0.0
Partial support 12.0.0
Notes
Notes 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.

Legend

Full support  
Full support
No support  
No support
See implementation notes.
See implementation notes.

See also