import type { FirstWeekContainsDateOptions, LocalizedOptions, WeekOptions, } from "./types.js"; /** * The {@link getWeekYear} function options. */ export interface GetWeekYearOptions extends LocalizedOptions<"options">, WeekOptions, FirstWeekContainsDateOptions {} /** * @name getWeekYear * @category Week-Numbering Year Helpers * @summary Get the local week-numbering year of the given date. * * @description * Get the local week-numbering year of the given date. * The exact calculation depends on the values of * `options.weekStartsOn` (which is the index of the first day of the week) * and `options.firstWeekContainsDate` (which is the day of January, which is always in * the first week of the week-numbering year) * * Week numbering: https://en.wikipedia.org/wiki/Week#The_ISO_week_date_system * * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc). * * @param date - The given date * @param options - An object with options. * * @returns The local week-numbering year * * @example * // Which week numbering year is 26 December 2004 with the default settings? * const result = getWeekYear(new Date(2004, 11, 26)) * //=> 2005 * * @example * // Which week numbering year is 26 December 2004 if week starts on Saturday? * const result = getWeekYear(new Date(2004, 11, 26), { weekStartsOn: 6 }) * //=> 2004 * * @example * // Which week numbering year is 26 December 2004 if the first week contains 4 January? * const result = getWeekYear(new Date(2004, 11, 26), { firstWeekContainsDate: 4 }) * //=> 2004 */ export declare function getWeekYear( date: DateType | number | string, options?: GetWeekYearOptions, ): number;