Function setWeekYear

pkgs/core/src/setWeekYear/index.ts:63–92

(
  date: DateArg<DateType>,
  weekYear: number,
  options?: SetWeekYearOptions<ResultDate>,
)

 * //=> Sat Jan 01 2005 00:00:00
 */
export function setWeekYear<
  DateType extends Date,
  ResultDate extends Date = DateType,
>(
  date: DateArg<DateType>,
  weekYear: number,
  options?: SetWeekYearOptions<ResultDate>,
): ResultDate {
  const defaultOptions = getDefaultOptions();
  const firstWeekContainsDate =
    options?.firstWeekContainsDate ??
    options?.locale?.options?.firstWeekContainsDate ??
    defaultOptions.firstWeekContainsDate ??
    defaultOptions.locale?.options?.firstWeekContainsDate ??
    1;

  const diff = differenceInCalendarDays(
    toDate(date, options?.in),
    startOfWeekYear(date, options),
    options,
  );

  const firstWeek = constructFrom(options?.in || date, 0);
  firstWeek.setFullYear(weekYear, 0, firstWeekContainsDate);
  firstWeek.setHours(0, 0, 0, 0);

  const date_ = startOfWeekYear(firstWeek, options);
  date_.setDate(date_.getDate() + diff);
  return date_;
}