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- "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;
- }
- }
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