diff --git a/lib/form/yui/dateselector/dateselector.js b/lib/form/yui/dateselector/dateselector.js
index e1394f3566f..1ea3669b9fe 100644
--- a/lib/form/yui/dateselector/dateselector.js
+++ b/lib/form/yui/dateselector/dateselector.js
@@ -137,10 +137,16 @@ YUI.add('moodle-form-dateselector', function(Y) {
             var year = parseInt(this.yearselect.get('value'));
             var month = parseInt(this.monthselect.get('value')) - 1;
             var day = parseInt(this.dayselect.get('value'));
-            M.form.dateselector.calendar.select(new Date(year, month, day));
+            var date = new Date(year, month, day);
+            M.form.dateselector.calendar.select(date);
             M.form.dateselector.calendar.setMonth(month);
             M.form.dateselector.calendar.setYear(year);
             M.form.dateselector.calendar.render();
+            if (date.getDate() != day) {
+                // Must've selected the 29 to 31st of a month that doesn't have such dates.
+                this.dayselect.set('value', date.getDate());
+                this.monthselect.set('value', date.getMonth() + 1);
+            }
         },
         set_selects_from_date : function(eventtype, args) {
             var date = args[0][0];