title: How to integrate Telerik DatePicker date format validation with Webforms ValidationSummary
body: <p>The Telerik DatePicker does not support the WebForms CompareValidator's data type check, because when an invalid date is entered, the DatePicker shows an error style on the input box, but returns an empty value.  So on a data entry form with optional date fields, some method is required to handle invalid dates so that they do not appear on postback to be empty fields.</p>