Gridview Updating, binding, parsing

Hi, I'm trying to parse a string from a textbox into a datetime type, in the following way:
<asp:TemplateField HeaderText="reminderDate" SortExpression="reminderDate" ConvertEmptyStringToNull="False" runat="server"> <EditItemTemplate> <asp:TextBox ID="reminderTB" runat="server" Text='<%# DateTime.Parse(Bind("reminderDate")) %>'></asp:TextBox> <asp:CalendarExtender ID="TextBox2_CalendarExtender" runat="server" Enabled="True" TargetControlID="reminderTB"></asp:CalendarExtender>
</EditItemTemplate>
But as you might've guessed it's not working. What's the simplest way to accomplish this parse?
I need it because the dbType is a datetime so ofcourse I can't update it with a string type.