public class DateComparer : IComparer    
{     
    public int Compare(object x, object y)     
    {     
        if ((x as RadDate).Date < (y as RadDate).Date)     
        {     
            return -1;     
        }     
        else if ((x as RadDate).Date > (y as RadDate).Date)     
        {     
            return 1;     
        }     
        else     
        {     
            return 0;     
        }     
    }     
}

Public Class DateComparer    
       Implements IComparer     
       Public Function Compare(ByVal x As Object, ByVal y As Object) As Integer Implements System.Collections.IComparer.Compare                 If (TryCast(x, Telerik.Web.UI.RadDate)).Date < (TryCast(y, Telerik.Web.UI.RadDate)).Date Then     
               Return -1     
           ElseIf (TryCast(x, Telerik.Web.UI.RadDate)).Date > (TryCast(y, Telerik.Web.UI.RadDate)).Date Then     
               Return 1     
           Else     
               Return 0     
           End If     
       End Function     
   End Class