TO_TIMESTAMP_TZ and unix timestamps

[supermega]

I have a table with a column filled with unix timestamps (how many seconds from whatever 1970) When people access that field it is not taking into account daylight saving time. Originally I was tasked with writing a huge case statement that would subtract an hour based on the time of year. I did a little digging and found the TO_TIMESTAMP_TZ function and read that it will handle all daylight saving time adjustments. So i set my timezone and restarted the db.

SQL> select dbtimezone from dual;

DBTI
----
EST

Then I made my TO_TIMESTAMP_TZ statement, 2 of them one a couple days before the DST change and one a couple days after, thinking that the 2nd one would display and hour before, but no change.


SQL>SELECT TO_TIMESTAMP_TZ('01/01/1970 00:00:00 EST', 'mm/dd/yyyy HH24:MI:SS TZD')
+ ((1112390687 / 86400) - (18000/86400))
FROM dual;
TO_TIMESTAMP_TZ('01/
--------------------
Apr 01 2005 16:24:47


SQL>SELECT TO_TIMESTAMP_TZ('01/01/1970 00:00:00 EST', 'mm/dd/yyyy HH24:MI:SS TZD')
+ ((1112649887/86400) - (18000/86400)) FROM dual;

TO_TIMESTAMP_TZ('01/
--------------------
Apr 04 2005 16:24:47

Anyone have any experience with this in the past?

SM

[supermega]

*BUMP*

anyone.....anyone....Bueller ???

[supermega]

wow!
im surprised no one has taken a stab at this one

--SM

[tamilselvan]

====
SQL>SELECT TO_TIMESTAMP_TZ('01/01/1970 00:00:00 EST', 'mm/dd/yyyy HH24:MI:SS TZD')
+ ((1112390687 / 86400) - (18000/86400))
FROM dual;
TO_TIMESTAMP_TZ('01/
--------------------
Apr 01 2005 16:24:47
========

What is the result you expect here?

You are adding a number after a date is formatted with TO_TIMESTAMP_TZ function.

Very few people use TO_TIMESTAMP_TZ format in real system. That is why you do not answer.

Hmm, Is TO_TIMESTAMP_TZ for OCP only ?

Tamil

[supermega]

hmmm... i see your point about doing the math after the timestamp conversion. i was doing it there because someone else tested it and found that if you did math in it the procedure returned a date instead of timestamp and the DST wasnt taken into account. my next guess would be do the math in a to_date and assign that to a variable and pass that variable to a to_timestamp_tz.

what i am hoping is if i pass Apr 04 2005 09:00 to a to_timestamp_tz oracle would return the time being 08:00 because it the date is in daylight daving time.

Thanks in advance,
--SM