SYSTIMESTAMP
SYSTIMESTAMP returns a TIMESTAMP WITH TIME ZONE for the database.
SQL> SELECT SYSTIMESTAMP FROM dual;
SYSTIMESTAMP
---------------------------------------------
08-JUL-12 10.23.09.087000 AM -07:00
SQL>
SQL> ALTER SESSION SET TIME_ZONE = 'EST';
Session altered.
SQL>
SQL> SELECT SYSTIMESTAMP FROM dual;
SYSTIMESTAMP
---------------------------------------------
08-JUL-12 10.23.09.134000 AM -07:00
SQL> ALTER SESSION SET TIME_ZONE = 'PST';
Session altered.
SQL>
SQL> SELECT SYSTIMESTAMP FROM dual;
SYSTIMESTAMP
---------------------------------------------
08-JUL-12 10.23.09.790000 AM -07:00
SQL>