Rad:Calendar has an option to show multiple months at a time and the FocusedDate property is used to set a month as starting month. This is also useful when you want to retrieve a stored Date from a database table and highlight it in the calendar. The Date obtained from the DB can be set as the default date in the RadCalendar1_DayRender Event.
But I had a situation in which I had to highlght multiple dates that are retirved from the Database table at one go . This no longer worked with the above code piece written in RadCalendar1_DayRender event. The trick here is to set the FocusedDate value in the page load Event of the page.