I want to disable weekend date using ajax calendar control.
Below  js code is working but its not disabled in calendar. How to do this using c#? 
function detect_sunday(sender, args) {
            if (sender._selectedDate.getDay() == 0) {
                sender._selectedDate = new Date();
                // set the date back to the current date
                sender._textbox.set_Value(sender._selectedDate.format(sender._format));
                //alert("You can't select sunday!");
                
            }
        }