Your problem is probably that the server is set to a different locale to your development machine.
If you dev machine is set to European dates DD/MM/YY and your server is set to US dates MM/DD/YY then you will get this effect because the Convert.ToDateTime method uses the current locale to decide how to evaluate the date.
Use the
DateTime.TryParseExact[
^] method instead - you can specify the date format exactly that way.