I have defined the global nls_date_format on Oracle 10.2 XE as follows:
alter system set nls_date_format=\'YYYY-MM-DD HH24:MI:SS\' scope=spfile;
Thanks, that worked for me. The trigger that I inserted is this:
CREATE OR REPLACE TRIGGER LOGINTRG AFTER LOGON ON DATABASE BEGIN EXECUTE IMMEDIATE 'ALTER SESSION SET NLS_DATE_FORMAT=''YYYY-MM-DD HH24:MI:SS'''; END LOGINTRG;
Set nls date format in an after logon trigger