📝 Commit Details:

backend/node_modules/date-fns/setISOWeekYear.js

@@ -0,0 +1,50 @@
+import { constructFrom } from "./constructFrom.js";
+import { differenceInCalendarDays } from "./differenceInCalendarDays.js";
+import { startOfISOWeekYear } from "./startOfISOWeekYear.js";
+import { toDate } from "./toDate.js";
+
+/**
+ * The {@link setISOWeekYear} function options.
+ */
+
+/**
+ * @name setISOWeekYear
+ * @category ISO Week-Numbering Year Helpers
+ * @summary Set the ISO week-numbering year to the given date.
+ *
+ * @description
+ * Set the ISO week-numbering year to the given date,
+ * saving the week number and the weekday number.
+ *
+ * ISO week-numbering year: http://en.wikipedia.org/wiki/ISO_week_date
+ *
+ * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows using extensions like [`UTCDate`](https://github.com/date-fns/utc).
+ * @typeParam ResultDate - The result `Date` type, it is the type returned from the context function if it is passed, or inferred from the arguments.
+ *
+ * @param date - The date to be changed
+ * @param weekYear - The ISO week-numbering year of the new date
+ * @param options - An object with options
+ *
+ * @returns The new date with the ISO week-numbering year set
+ *
+ * @example
+ * // Set ISO week-numbering year 2007 to 29 December 2008:
+ * const result = setISOWeekYear(new Date(2008, 11, 29), 2007)
+ * //=> Mon Jan 01 2007 00:00:00
+ */
+export function setISOWeekYear(date, weekYear, options) {
+  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;
+}
+
+// Fallback for modularized imports:
+export default setISOWeekYear;