Intl.RelativeTimeFormat.prototype.format()

The Intl.RelativeTimeFormat.prototype.format() method formats a value and unit according to the locale and formatting options of this 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
Intl.RelativeTime proposal Stage 3  

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 No support No Firefox Full support 65 IE No support No Opera Full support 58 Safari No support No WebView Android Full support 71 Chrome Android Full support 71 Firefox Android Full support 65 Opera Android Full support 50 Safari iOS No support No Samsung Internet Android Full support 10.0 nodejs Full support 12.0.0

Legend

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