The format() method of Intl.RelativeTimeFormat instances formats a value and unit according to the locale and formatting options of this Intl.RelativeTimeFormat object.
Syntax
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.
- : Unit to use in the relative time internationalized message. Possible values are:
Return value
A string representing the given value and unit formatted 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, today, or tomorrow instead of 1 day ago, in 0 days, 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"
rtf.format(0, "day"); // "today"
// Format relative time using positive day unit (1).
rtf.format(1, "day"); // "tomorrow"