DateTime Oracle

http://www.dba-oracle.com/t_date_math_manipulation.htm
http://www.psoug.org/reference/date_func.html
http://www.akadia.com/services/ora_date_time.html

ALTER SESSION SET TIME_ZONE = '+7:0';

select sysdate from dual

select add_months( sysdate,2)
from dual



select user_id,
to_char( to_date('01011970','ddmmyyyy') + 1/24/60/60 * view_date, 'dd-mm-yyyy hh24:mi:ss') AS TS2Date,
to_char( to_date('01011970','ddmmyyyy') + 1/24/60/60 * view_date, 'mm-yyyy') AS TS2Date2,
score,
max_score,
pass_score,
result,
course_id
from test_history


select sysdate + 1/24/60/60 + 420/1440
from dual

select sysdate + 1/24/60/60
from dual;

select sysdate + 420/24/60
from dual

select to_date('01011970','ddmmyyyy') + 1/24/60/60
from dual

select TRUNC(SYSDATE+1/24,'HH')
from dual