You can call the SQLDriverConnect or the SQLBrowseConnect API function, and use the new DATETIMEFORMAT = XYZ option. The DateTimeFormat is only valid for the duration of the new session. You can also use one of the following SQL statements to permanently set it:
SET SESSION DATEFORM = INTEGERDATE SET SESSION DATEFORM = ANSIDATE
The DateTimeFormat is only valid for the duration of the session. In addition, the SET SESSION DATEFORM SQL statement must not be included in a multi-statement request. Finally, this method only sets the DATE format. The TIME and TIMESTAMP formats still come from the DSN options.