I have a calender control tht you can click on. When you click on a date you see all the events that happens that date. But i want the calender to show what dates have events. I want these dates to have a seperate styling. In the code behind i catch the DayRender event. I have a list will all important dates called "eventDates". if (eventDates.Contains(e.Day.Date) == true) { Calendar1.SelectedDates.Add(e.Day.Date);