In this example we demonstrate the 
RangeSelectionChanged server-side event of the 
RadDateRangePicker:
    
        - RangeSelectionChanged - it fires on postback, only if the Start or/and End dates have been changed.
    In the demo we have used the 
DateSelected client-side event and the set_shouldPostback() function exposed in the EventArguments object to automaticaly trigger a postback and submit the changes to the server when both Start and End date have been selected.
    function OnDateSelected(sender, args) {
        
//trigger a postback when both start and end dates are selected 
        if (sender.get_rangeSelectionStartDate() && sender.get_rangeSelectionEndDate()) { 
            args.set_shouldPostBack(true);
        }
    }
    
    You can use the Submit button to commit the changes to the server when either Start or End date (or both) is not selected.