Web/JavaScript/Reference/Global objects/Intl/RelativeTimeFormat/format

The Intl.RelativeTimeFormat.prototype.format() method formats a value and unit according to the locale and formatting options of this Intl.RelativeTimeFormat object.

Syntax

relativeTimeFormat.format(value, unit)

Parameters

value: Numeric value to use in the internationalized relative time message.

unit: Unit to use in the relative time internationalized message. Possible values are: "year", "quarter", "month", "week", "day", "hour", "minute", "second". Plural forms are also permitted.

Description

The function returned by the format getter formats a value and a unit into a string according to the locale and formatting options of this Intl.RelativeTimeFormat object.

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.format()' in that specification.	Stage 4

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
`format`	Chrome Full support 71	Edge Full support 79	Firefox Full support 65	IE No support No	Opera Full support 58	Safari Full support 14	WebView Android Full support 71	Chrome Android Full support 71	Firefox Android Full support 65	Opera Android Full support 50	Safari iOS Full support 14	Samsung Internet Android Full support 10.0	nodejs Full support 12.0.0 Notes' Full support 12.0.0 Notes' Notes' Before version 13.0.0, only the locale data for `en-US` is available by default. See the `RelativeTimeFormat()` constructor for more details.

Legend

Full support: Full support
No support: No support
See implementation notes.': See implementation notes.