import { constructFrom } from "./constructFrom.mjs"; import { getWeekYear } from "./getWeekYear.mjs"; import { startOfWeek } from "./startOfWeek.mjs"; import { getDefaultOptions } from "./_lib/defaultOptions.mjs"; /** * The {@link startOfWeekYear} function options. */ /** * @name startOfWeekYear * @category Week-Numbering Year Helpers * @summary Return the start of a local week-numbering year for the given date. * * @description * Return the start of a local week-numbering year. * 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 original date * @param options - An object with options * * @returns The start of a week-numbering year * * @example * // The start of an a week-numbering year for 2 July 2005 with default settings: * const result = startOfWeekYear(new Date(2005, 6, 2)) * //=> Sun Dec 26 2004 00:00:00 * * @example * // The start of a week-numbering year for 2 July 2005 * // if Monday is the first day of week * // and 4 January is always in the first week of the year: * const result = startOfWeekYear(new Date(2005, 6, 2), { * weekStartsOn: 1, * firstWeekContainsDate: 4 * }) * //=> Mon Jan 03 2005 00:00:00 */ export function startOfWeekYear(date, options) { const defaultOptions = getDefaultOptions(); const firstWeekContainsDate = options?.firstWeekContainsDate ?? options?.locale?.options?.firstWeekContainsDate ?? defaultOptions.firstWeekContainsDate ?? defaultOptions.locale?.options?.firstWeekContainsDate ?? 1; const year = getWeekYear(date, options); const firstWeek = constructFrom(date, 0); firstWeek.setFullYear(year, 0, firstWeekContainsDate); firstWeek.setHours(0, 0, 0, 0); const _date = startOfWeek(firstWeek, options); return _date; } // Fallback for modularized imports: export default startOfWeekYear;