I'm adding a DateTime DataColumn to a DataTable like this:

Code:
Dim colDate As DataColumn = New DataColumn("Date")
            colDate.DataType = System.Type.GetType("System.DateTime")
            dt.Columns.Add(colDate)

Then when I try to add it to my datatable, if the value is Nothing I get an error saying string was not recognized as a valid DateTime. I'm having trouble getting this to work. What would you do?

Thanks