Problem: Database doesnt start. After playing with the fixed_date and then unsetting it with NONE option, I rebooted the machine later; tried to restart Oracle. Logged into sqlplus /nolog as sysdba then:
16:34:40 SQL> show user; USER is "SYS" 16:35:00 SQL> startup mount; ORA-00065 (See ORA-00065.ora-code.com): initialization of FIXED_DATE failed
16:35:43 SQL> alter system set fixed_date=NONE; alter system set fixed_date=NONE * ERROR at line 1: ORA-01034 (See ORA-01034.ora-code.com): ORACLE not available
16:37:58 SQL> alter system set fixed_date='23-DEC-2004'; alter system set fixed_date='23-DEC-2004' * ERROR at line 1: ORA-01034 (See ORA-01034.ora-code.com): ORACLE not available