If you are using ComponentOne for .NET 2.0 then you also have a C1 control installed called C1WebDateEdit. This control can be used to enter dates or times or both. This control only allows valid date/time input so that level of validation is simple.
To get this control into a WebGrid you can set up a Template Column. This is best done in the designer mode through the "Columns" editor. The C1WebDateEdit control should be placed in the ItemTemplate. The template column can be bound to a datafield by clicking "Set Databindings" from the ItemTemplate.
Let me know if you'd like a sample
Regards,
Greg L