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Home -> Community -> Mailing Lists -> Oracle-L -> RE: NEW TIME ZONE
Quite a few products store dates as elapsed seconds after '01-JAN-1970:00:00:00' GMT, but users here want to see the local time of the stored date. Of course PST is 8 hours behind GMT and PDT is seven hours so a hard coded offfset will not work. Also the dates on which the change is made from PST to PDT and back changes. So I thought why not a function...
CREATE OR REPLACE PACKAGE REMEDY IS
FUNCTION SLAC_DATE(ELAPSED_SECONDS IN NUMBER) RETURN DATE ;
PRAGMA RESTRICT_REFERENCES(SLAC_DATE,WNDS, RNDS, TRUST);
END REMEDY;
FUNCTION SLAC_DATE(ELAPSED_SECONDS IN NUMBER) RETURN DATE is
is_pdt boolean;
GMT_TIME VARCHAR2(19);
YEAR_OF_DATE VARCHAR2(4);
PDT_BEGIN VARCHAR2(19);
PDT_END VARCHAR2(19);
local_time date;
bEGIN
GMT_TIME := TO_CHAR(TO_DATE('01011970000000', 'MMDDYYYYHH24MISS') + (ELAPSED_SECONDS /(60 *60 * 24)), 'YYYYMMDDHH24MISS'); year_of_date := substr(GMT_TIME, 1,4); PDT_BEGIN := to_char(TRUNC(to_date(concat('31-MAR-',year_of_date),
'DD-MON-YYYY'), 'IW') +6 +10/24, 'YYYYMMDDHH24MISS'); PDT_END := to_char(TRUNC(to_date(concat('01-NOV-', year_of_date),
'DD-MON-YYYY'), 'IW') -1 +9/24,'YYYYMMDDHH24MISS'); IF GMT_TIME >= PdT_BEGIN AND GMT_TIME < PDT_END THEN
is_pdt := true;
ELSE
is_pdt := false;
end if;
if is_pdt then
local_time := to_date(gmt_time,'YYYYMMDDHH24MISS') -7/24; else
local_time := to_date(gmt_time,'YYYYMMDDHH24MISS') -8/24;
end if;
return local_time;
end SLAC_DATE;
end remedy;
/
This function takes a Remedy date , elapsed seconds after the "epoch" and converts it
to GMT it then
obtains the year from the date ,figures when the switch was made between PDT and PST
that year, and returns what the local date and time was.
Of couse not every place makes the switch to daylight savings at 10 a.m. GMT on the first Sunday in April nor to standard time at 9 a.m. GMT on the last Sunday in October, and the rules for when to switch have changed before and could again.
There are 25 major time zones in the world. 23 which are 15 degrees wide and two which are 7.5 degrees in width. The International Dateline splits the two 7.5 degree timezones.
Old American joke: "The world will end at nine, eight Central Time. Old Canadian joke: "The world will end at nine, nine-thirty in Newfoundland."
Ian MacGregor
Stanford Linear Accelerator Ceneter
ian_at_slac.stanford.edu
-----Original Message-----
Sent: Wednesday, June 06, 2001 2:32 PM
To: Multiple recipients of list ORACLE-L
As I've mentioned here before, NEW_TIME does not automatically handle DST conversions. Nor does it take care of the several places in the US that do not use DST such as Eastern Indiana and Arizona. You need to write your own code to manage time zones and DST conversions. For a good source of the time zones and DST rules in effect, check out www.timeanddate.com. And keep in mind the DST rules and start/end dates can and do change every year depending on the whims of governments.
Marc Perkowitz
Senior Consultant
TWJ Consulting, LLP
847-256-8866 x15
www.twjconsulting.com
> Hi All!
> New_time function use just 10 US time zones. I am looking for other world
> time zones.
> Any ideas?
> Thanks.
> Greg.
>
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> --
> Author: Gregory Faktor
> INET: gfaktor_at_ecal.com
>
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-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Marc Perkowitz INET: mperkowitz_at_twjconsulting.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: MacGregor, Ian A. INET: ian_at_SLAC.Stanford.EDU Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).Received on Wed Jun 06 2001 - 20:50:51 CDT
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