📝 Commit Details:

backend/node_modules/date-fns/endOfDecade.js

@@ -0,0 +1,41 @@
+import { toDate } from "./toDate.js";
+
+/**
+ * The {@link endOfDecade} function options.
+ */
+
+/**
+ * @name endOfDecade
+ * @category Decade Helpers
+ * @summary Return the end of a decade for the given date.
+ *
+ * @description
+ * Return the end of a decade for the given date.
+ *
+ * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use 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 original date
+ * @param options - An object with options
+ *
+ * @returns The end of a decade
+ *
+ * @example
+ * // The end of a decade for 12 May 1984 00:00:00:
+ * const result = endOfDecade(new Date(1984, 4, 12, 00, 00, 00))
+ * //=> Dec 31 1989 23:59:59.999
+ */
+export function endOfDecade(date, options) {
+  // TODO: Switch to more technical definition in of decades that start with 1
+  // end with 0. I.e. 2001-2010 instead of current 2000-2009. It's a breaking
+  // change, so it can only be done in 4.0.
+  const _date = toDate(date, options?.in);
+  const year = _date.getFullYear();
+  const decade = 9 + Math.floor(year / 10) * 10;
+  _date.setFullYear(decade, 11, 31);
+  _date.setHours(23, 59, 59, 999);
+  return _date;
+}
+
+// Fallback for modularized imports:
+export default endOfDecade;