如何在ValidationSummary中为无效的用户输入提供有用的错误消息？

Scenario: A user enters a string in the DateTime field. A * appears when a postback occurs but no message in a ValidationSummary. I have tried implementing IDataErrorInfo but the code never falls through IDataErrorInfo.this[string columnName] for the EventDate field. I have tried implementing DataAnnotations attributes again this doesn't work. By the time code reaches the attribute checks the EventDate has been changed to DateTime.MinValue by the framework.Scenario: A user enters a string in the DateTim