GridDataTimeColumn and RadDataPicker

[Jhon]

Good afternoon, my name is John and I work in Brazil. I'm doing a project and use some components of Telerik, but I doubt that this is a difficult problem.
The problem is that I can not leave my GridDataTimeColumn in an empty field, I mean, is not required the user to select a specific date.
Only I would like the field of my GridDataTimeColumn stay empty if the user selects not the date on RadDataPicker.

The lower image is an example that you reported, I could not understand what the code that makes this event. How you guys managed to leave the column blank DataTimeColumn, if I do not select a specific date?

Thank you for your attention!

[Jayesh Goyani]

Hello Jhon,

<telerik:GridDateTimeColumn PickerType="DateTimePicker" DataField="customdate" UniqueName="DateTimeColumn">
                   </telerik:GridDateTimeColumn>

protected void RadGrid1_ItemCreated(object sender, GridItemEventArgs e)
   {
       if (e.Item is GridEditableItem && e.Item.IsInEditMode)
       {
           GridDateTimeColumnEditor columnEditor =
               ((GridEditableItem)e.Item).EditManager.GetColumnEditor("DateTimeColumn") as GridDateTimeColumnEditor;

           TableCell cell = (TableCell)columnEditor.PickerControl.Parent;

           RequiredFieldValidator compareValidator = new RequiredFieldValidator();
           compareValidator.ID = "compareValidator";
           compareValidator.ControlToValidate = columnEditor.PickerControl.ID;

           compareValidator.ErrorMessage = "please provide date";

           cell.Controls.Add(compareValidator);
       }
   }

Thanks,
Jayesh Goyani