Dirk mentioned an
issue he was having with Oracle 9i not picking up the
nls_date_format value as expected.
If this hasn't already been resolved try setting the nls_lang value first, eg:
export NLS_LANG=American_America
export NLS_DATE_FORMAT="YYYY-MM-DD"
More information can be found in the Oracle 9i Database Globalization Support Guide Release 2 (Chapter 3) - link (requires on Oracle OTN account).
Regards,
AndyC
