Refs #24980 -- Fixed incorrect timezone handling in admin calendar widget.

django/contrib/admin/static/admin/js/admin/DateTimeShortcuts.js

@@ -368,8 +368,8 @@
             if (inp.value) {
                 var format = get_format('DATE_INPUT_FORMATS')[0];
                 var selected = inp.value.strptime(format);
-                var year = selected.getFullYear();
-                var month = selected.getMonth() + 1;
+                var year = selected.getUTCFullYear();
+                var month = selected.getUTCMonth() + 1;
                 var re = /\d{4}/;
                 if (re.test(year.toString()) && month >= 1 && month <= 12) {
                     DateTimeShortcuts.calendars[num].drawDate(month, year, selected);