How to get exact date and time difference?

Question

Hi,
When i am using the below sql statement:
SELECT (TO_DATE('7/27/2006 05:00:15 PM','MM/DD/YYYY HH:MI:SS PM') - to_Date('7/27/2006 8:30:13 AM','MM/DD/YYYY HH:MI:SS AM')) * 24 hours FROM DUAL;
the output is:
Hours
8.50055555555556
But Actually it is 8.30
So how can i get exact days and time difference between two dates in Oracle?
Thanks....
Regards,
Suman Sakinala
Edited by: SSN on Sep 19, 2008 1:27 AM

Answer 1

Or more clearly (this time I have my date_from and date_to the right way around hehe!)
SQL> ed
Wrote file afiedt.buf
  1  WITH t as (select TO_DATE('7/27/2006 05:00:15 PM','MM/DD/YYYY HH:MI:SS PM') as dt_to,
  2                    TO_DATE('7/27/2006 08:30:13 AM','MM/DD/YYYY HH:MI:SS AM') as dt_from FROM DUAL)
  3      ,d as (select (dt_to-dt_from)*24 as diff_hrs from t)
  4  -- end of dates
  5  SELECT TRUNC(diff_hrs) as hours
  6        ,TRUNC(((diff_hrs) - TRUNC(diff_hrs))*60) as mins
  7        ,TRUNC(((((diff_hrs) - TRUNC(diff_hrs))*60) - TRUNC(((diff_hrs) - TRUNC(diff_hrs))*60))*60) as secs
  8* FROM d
SQL> /
     HOURS       MINS       SECS
         8         30          2
SQL>