"use strict"; exports.getISOWeekYear = getISOWeekYear; var _index = require("./constructFrom.cjs"); var _index2 = require("./startOfISOWeek.cjs"); var _index3 = require("./toDate.cjs"); /** * The {@link getISOWeekYear} function options. */ /** * @name getISOWeekYear * @category ISO Week-Numbering Year Helpers * @summary Get the ISO week-numbering year of the given date. * * @description * Get the ISO week-numbering year of the given date, * which always starts 3 days before the year's first Thursday. * * ISO week-numbering year: http://en.wikipedia.org/wiki/ISO_week_date * * @param date - The given date * * @returns The ISO week-numbering year * * @example * // Which ISO-week numbering year is 2 January 2005? * const result = getISOWeekYear(new Date(2005, 0, 2)) * //=> 2004 */ function getISOWeekYear(date, options) { const _date = (0, _index3.toDate)(date, options?.in); const year = _date.getFullYear(); const fourthOfJanuaryOfNextYear = (0, _index.constructFrom)(_date, 0); fourthOfJanuaryOfNextYear.setFullYear(year + 1, 0, 4); fourthOfJanuaryOfNextYear.setHours(0, 0, 0, 0); const startOfNextYear = (0, _index2.startOfISOWeek)( fourthOfJanuaryOfNextYear, ); const fourthOfJanuaryOfThisYear = (0, _index.constructFrom)(_date, 0); fourthOfJanuaryOfThisYear.setFullYear(year, 0, 4); fourthOfJanuaryOfThisYear.setHours(0, 0, 0, 0); const startOfThisYear = (0, _index2.startOfISOWeek)( fourthOfJanuaryOfThisYear, ); if (_date.getTime() >= startOfNextYear.getTime()) { return year + 1; } else if (_date.getTime() >= startOfThisYear.getTime()) { return year; } else { return year - 1; } }