SELECT TIME '19:00:00'+INTERVAL '9' HOUR, TIME '19:00:00'-INTERVAL '9' HOUR  from dual;
SELECT TIME '19:00:00'+INTERVAL '9' DAY, TIME '19:00:00'-INTERVAL '9' DAY  from dual;
SELECT TIME '19:00:00'+INTERVAL '9' SECOND, TIME '19:00:00'-INTERVAL '9' SECOND  from dual;
