📝 Commit Details:

backend/node_modules/date-fns/differenceInCalendarISOWeekYears.js

@@ -0,0 +1,48 @@
+import { normalizeDates } from "./_lib/normalizeDates.js";
+import { getISOWeekYear } from "./getISOWeekYear.js";
+
+/**
+ * The {@link differenceInCalendarISOWeekYears} function options.
+ */
+
+/**
+ * @name differenceInCalendarISOWeekYears
+ * @category ISO Week-Numbering Year Helpers
+ * @summary Get the number of calendar ISO week-numbering years between the given dates.
+ *
+ * @description
+ * Get the number of calendar ISO week-numbering years between the given dates.
+ *
+ * ISO week-numbering year: http://en.wikipedia.org/wiki/ISO_week_date
+ *
+ * @param laterDate - The later date
+ * @param earlierDate - The earlier date
+ * @param options - An object with options
+ *
+ * @returns The number of calendar ISO week-numbering years
+ *
+ * @example
+ * // How many calendar ISO week-numbering years are 1 January 2010 and 1 January 2012?
+ * const result = differenceInCalendarISOWeekYears(
+ *   new Date(2012, 0, 1),
+ *   new Date(2010, 0, 1)
+ * )
+ * //=> 2
+ */
+export function differenceInCalendarISOWeekYears(
+  laterDate,
+  earlierDate,
+  options,
+) {
+  const [laterDate_, earlierDate_] = normalizeDates(
+    options?.in,
+    laterDate,
+    earlierDate,
+  );
+  return (
+    getISOWeekYear(laterDate_, options) - getISOWeekYear(earlierDate_, options)
+  );
+}
+
+// Fallback for modularized imports:
+export default differenceInCalendarISOWeekYears;