Thanks for the input.

The issue was resolved by also setting NLS_TIMESTAMP_FORMAT='YYYY-MM-DD-HH24.MI.SS.FF';

Otherwise get the error:
SQL> INSERT INTO ADMIN.RESUEST VALUES(1, 1, DEFAULT, 1, DEFAULT, DEFAULT);
INSERT INTO ADMIN.RESUEST VALUES(1, 1, DEFAULT, 1, DEFAULT, DEFAULT)
*
ERROR at line 1:
ORA-01847: day of month must be between 1 and last day of month
SQL>

Thanks once again.