Function setISOWeekYear

pkgs/core/src/setISOWeekYear/index.ts:39–58

(
  date: DateArg<DateType>,
  weekYear: number,
  options?: SetISOWeekYearOptions<ResultDate> | undefined,
)

 * //=> Mon Jan 01 2007 00:00:00
 */
export function setISOWeekYear<
  DateType extends Date,
  ResultDate extends Date = DateType,
>(
  date: DateArg<DateType>,
  weekYear: number,
  options?: SetISOWeekYearOptions<ResultDate> | undefined,
): ResultDate {
  let _date = toDate(date, options?.in);
  const diff = differenceInCalendarDays(
    _date,
    startOfISOWeekYear(_date, options),
  );
  const fourthOfJanuary = constructFrom(options?.in || date, 0);
  fourthOfJanuary.setFullYear(weekYear, 0, 4);
  fourthOfJanuary.setHours(0, 0, 0, 0);
  _date = startOfISOWeekYear(fourthOfJanuary);
  _date.setDate(_date.getDate() + diff);
  return _date;
}