Datepicker: Account for daylight saving when calculating number of da…

…ys in a month. Fixes #6978 - In Calender for march 2011 dates showing till 5th only.

Thanks jomyjohn
(cherry picked from commit c44818f)

ui/jquery.ui.datepicker.js

@@ -1656,7 +1656,7 @@ $.extend(Datepicker.prototype, {
 
 	/* Find the number of days in a given month. */
 	_getDaysInMonth: function(year, month) {
-		return 32 - new Date(year, month, 32).getDate();
+		return 32 - this._daylightSavingAdjust(new Date(year, month, 32)).getDate();
 	},
 
 	/* Find the day of the week of the first of a month. */