You should be able to set NLS_DATE_FORMAT on the Solaris box, either in the environment of nsadmin or in the script that starts nsd. E.g. just did this from one of our Linux boxes to a Win2000 database:
[oracle@qfs18 oracle]$ sqlplus crga/crga@oemrep
SQL*Plus: Release 8.1.7.0.0 - Production on Thu Feb 26 17:18:09 2004
(c) Copyright 2000 Oracle Corporation. All rights reserved.
Connected to:
Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.1.0 - Production
SQL> select sysdate from dual;
SYSDATE
----------
2004-02-26
SQL> quit
Disconnected from Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.1.0 - Production
[oracle@qfs18 oracle]$ export NLS_DATE_FORMAT="DD-MM-YYYY"
[oracle@qfs18 oracle]$ sqlplus crga/crga@oemrep
SQL*Plus: Release 8.1.7.0.0 - Production on Thu Feb 26 17:18:27 2004
(c) Copyright 2000 Oracle Corporation. All rights reserved.
Connected to:
Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.1.0 - Production
SQL> select sysdate from dual;
SYSDATE
----------
26-02-2004
SQL>