Intl.Locale.prototype.getWeekInfo()

Baseline Newly available

This feature works across the latest devices and browser versions. This feature might not work in older devices or browser versions. It's been available across browsers since July 2026.

The getWeekInfo() method of Intl.Locale instances returns a weekInfo object with the properties firstDay, weekend and minimalDays for this locale.

Note: In some versions of some browsers, this method was implemented as an accessor property called weekInfo. However, because it returns a new object on each access, it is now implemented as a method to prevent the situation of locale.weekInfo === locale.weekInfo returning false. Check the browser compatibility table for details.

Syntax

getWeekInfo()

Parameters

None.

Return value

An object representing week information associated with the Locale data specified in UTS 35's Week Elements. It has the following properties:

firstDay: An integer between 1 (Monday) and 7 (Sunday) indicating the first day of the week for the locale. Commonly 1, 5, 6, or 7.
weekend: An array of integers between 1 and 7 indicating the weekend days for the locale. This is usually continuous because UTS 35 stores weekendStart and weekendEnd instead.
minimalDays: An integer between 1 and 7 (commonly 1 and 4) indicating the minimal days required in the first week of a month or year, for week-of-year or week-of-month calculations (e.g., The 20th week of the year). For example, in the ISO 8601 calendar, the first week of a year must have at least 4 days in this year, so if January 1 is a Friday, Saturday, or Sunday, it will be numbered as part of the last week of the previous year.

Examples

Obtaining the Week Information

Return the week information for a given Locale.

const he = new Intl.Locale("he"); // Hebrew (Israel)
console.log(he.getWeekInfo()); // { firstDay: 7, weekend: [5, 6], minimalDays: 1 }

const af = new Intl.Locale("af"); // Afrikaans (South Africa)
console.log(af.getWeekInfo()); // { firstDay: 7, weekend: [6, 7], minimalDays: 1 }

const enGB = new Intl.Locale("en-GB"); // English (United Kingdom)
console.log(enGB.getWeekInfo()); // { firstDay: 1, weekend: [6, 7], minimalDays: 4 }

const arAF = new Intl.Locale("ar-AF"); // Arabic (Afghanistan)
console.log(arAF.getWeekInfo()); // { firstDay: 6, weekend: [4, 5], minimalDays: 1 }

const dvMV = new Intl.Locale("dv-MV"); // Divehi (Maldives)
console.log(dvMV.getWeekInfo()); // { firstDay: 5, weekend: [6, 7], minimalDays: 1 }

Specifications

Specification
Intl Locale Info Proposal # sec-Intl.Locale.prototype.getWeekInfo

Browser compatibility

	Desktop					Mobile							Server
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on iOS	Samsung Internet	WebView Android	WebView on iOS	Bun	Deno	Node.js
`getWeekInfo`	130 99 Implemented as an accessor property.	130 99 Implemented as an accessor property.	153	115 85 Implemented as an accessor property.	17 15.4–preview Implemented as an accessor property.	130 99 Implemented as an accessor property.	153	86 68 Implemented as an accessor property.	17 15.4 Implemented as an accessor property.	28.0 18.0 Implemented as an accessor property.	130 99 Implemented as an accessor property.	17 15.4 Implemented as an accessor property.	1.0.0	2.1 1.19–2.6.7 Implemented as an accessor property.	24.0.0 18.0.0 Implemented as an accessor property.
`returns_minimalDays_property`	99–136	99–136	No	85–121	15.4	99–136	No	68–90	15.4	18.0–29.0	99–136	15.4	1.0.0	1.19	18.0.0–24.0.0