As stated earlier, a DTP control relies on a format string to determine how it will display fields of information. By default, a DTP control can display time information in the format DTS_LONGDATEFORMAT.
Custom format strings provide flexibility for your application. In a custom format string, you can specify the order that the control will display fields of information or indicate specific callback fields. The format characters that comprise the format string define the DTP control's display and field layout.