Intl.RelativeTimeFormat

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2020.

The Intl.RelativeTimeFormat object enables language-sensitive relative time formatting.

Try it

Constructor

Intl.RelativeTimeFormat()

Creates a new Intl.RelativeTimeFormat object.

Static methods

Intl.RelativeTimeFormat.supportedLocalesOf()

Returns an array containing those of the provided locales that are supported without having to fall back to the runtime's default locale.

Instance properties

These properties are defined on Intl.RelativeTimeFormat.prototype and shared by all Intl.RelativeTimeFormat instances.

Intl.RelativeTimeFormat.prototype.constructor

The constructor function that created the instance object. For Intl.RelativeTimeFormat instances, the initial value is the Intl.RelativeTimeFormat constructor.

Intl.RelativeTimeFormat.prototype[Symbol.toStringTag]

The initial value of the [Symbol.toStringTag] property is the string "Intl.RelativeTimeFormat". This property is used in Object.prototype.toString().

Instance methods

Intl.RelativeTimeFormat.prototype.format()

Formats a value and a unit according to the locale and formatting options of the given Intl.RelativeTimeFormat object.

Intl.RelativeTimeFormat.prototype.formatToParts()

Returns an Array of objects representing the relative time format in parts that can be used for custom locale-aware formatting.

Intl.RelativeTimeFormat.prototype.resolvedOptions()

Returns a new object with properties reflecting the locale and formatting options computed during initialization of the object.

Examples

Basic format usage

The following example shows how to use a relative time formatter for the English language.

js
// 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 formatToParts

The following example shows how to create a relative time formatter returning formatted parts.

js
const rtf = new Intl.RelativeTimeFormat("en", { numeric: "auto" });

// Format relative time using the day unit.
rtf.formatToParts(-1, "day");
// [{ type: "literal", value: "yesterday"}]

rtf.formatToParts(100, "day");
// [
//   { type: "literal", value: "in " },
//   { type: "integer", value: "100", unit: "day" },
//   { type: "literal", value: " days" }
// ]

Specifications

Specification
ECMAScript Internationalization API Specification
# relativetimeformat-objects

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
RelativeTimeFormat
RelativeTimeFormat() constructor
locales parameter
format
formatToParts
resolvedOptions
supportedLocalesOf

Legend

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Full support
Full support
Partial support
Partial support
See implementation notes.
Has more compatibility info.

See also