topic Re: Daylight saving time in Operating System - HP-UX

Daylight saving time

Chris Harris_1 — Wed, 03 Apr 2002 13:27:42 GMT

Hi guys,

this is my first post, hope you can help. We have a customer running an application on a HP9000 server ( hp-ux 11.0 ). When the clocks went forward this weekend, for some reason the hp machine did not go forward as I expected it to. I manually put the date forward using the 'date' command. However, even though the machine now has the correct date, the application logs are still date stamping one hour behind. The value of the TZ variable is MET-1.

Thanks in advance,

Chris.

Re: Daylight saving time

Marc Dijkstra — Wed, 03 Apr 2002 13:31:51 GMT

Hi there

Check the dst (daylight saving time) parameter in the kernel configuration with SAM to make sure it is set on.

MND

Re: Daylight saving time

harry d brown jr — Wed, 03 Apr 2002 13:40:39 GMT

Chris,

I didn't know that the UK went into DST before the US, interesting!

Did you start and stop your application?

live free or die
harry

Re: Daylight saving time

Frank Quinteros — Wed, 03 Apr 2002 13:52:23 GMT

Chris I am a little confused, its my understanding that the clock 'springs' forward this coming weekend 4/7/02 @ 02:00EST to 03:00EDT.
Marc is right, if the current value of the dst kernel parameter is = 1 then you should be OK.
I will be watching tasks that are scheduled to run at 2:15EST but because the clock will never get to 02:15EST but jump to 03:00EDT on the next minute after 01:59EST. I expect my job to run starting at 03:00EDT.
Hope my comment does not confuse you.
If I am in the wrong, someone !please correct me!

Re: Daylight saving time

Robert Gamble — Wed, 03 Apr 2002 14:07:10 GMT

Chris, were you the victim of an April Fool's joke ? You switched your time already ?

I have been through your scenario before though. If the job is scheduled to kick off at 02:15, it will not run. All jobs scheduled to run between 02:01 and 02:59 will not happen. You will have to create an `at` job on this one day of the year.

Good Luck!

Re: Daylight saving time

Paula J Frazer-Campbell — Wed, 03 Apr 2002 14:10:52 GMT

Chris

It looks like you are getting a GMT time stamp - when you set the time did you use date -u ? This is incorrect for UK at present.

Try date mmddhhmm

Paula

Re: Daylight saving time

Trond Haugen — Wed, 03 Apr 2002 14:17:45 GMT

In short the system hasn't been set up to adjust for DST.
With TZ=MET-1 you have just set the timezone. If you had wanted the system to automatically adjust to DST it should have been set to MET-1METDST. You should change this with 'set_parms timezone'. As Harry said you will need to restart the application.
As for the tomezone and dst parameters in the kernel verry few applications use them but I can't say if yours don't. But it will not hurt to change them.
Robert; he's not been the victim of an April Fool's joke. According to /usr/lib/tztab "we" changed last weekend:
# Middle European Time, Middle European Time Daylight Savings Time
MET-1METDST
0 3 25-31 3 1983-2038 0 METDST-2
0 2 24-30 9 1983-1995 0 MET-1
0 2 25-31 10 1996-2038 0 MET-1

Hope this helps,
Trond

Re: Daylight saving time

harry d brown jr — Wed, 03 Apr 2002 14:17:54 GMT

The Summer Time Act 1972 defined the period of British Summer Time to start at 2 am (GMT) on the morning of the day after the third Saturday in March or, if that was Easter Day, the day after the second Saturday. It was to end at 2 am (GMT) on the day after the fourth Saturday in October.

The duration of British Summer Time (BST) can be varied by Order of Council and in recent years has been changed so as to bring the date of the start of Summer Time into line with that used in Europe.

In 2002 an order was made to link UK summer time to Europe permanently. This means that the clocks will change over the Easter weekend which historically has not be the case.

http://greenwichmeantime.com/info/bst.htm

I learned something new, can I go home now?

live free or die
harry

Re: Daylight saving time

Frank Quinteros — Wed, 03 Apr 2002 14:53:38 GMT

On servers that are currently running GMT,

when exactly are these servers flipping to BST?

Is it the same time as when EST goes to EDT?

Re: Daylight saving time

Chris Harris_1 — Wed, 03 Apr 2002 15:09:07 GMT

Thanks for all your responses. I have much more to go on now.

cheers,

Chris.

Re: Daylight saving time

Paula J Frazer-Campbell — Wed, 03 Apr 2002 15:12:58 GMT

Hi Frank

BST is between March and Oct and during that period it is GMT+1.

The Spring forward - Autum (Fall) back applies.

paula

Re: Daylight saving time

Frank Slootweg — Fri, 05 Apr 2002 13:04:41 GMT

Hi Chris,

Now that you have been helped, can you please assign points? See the "how to earn points" link in the 'upper' left blue part of this page, i.e. the part where also all the different types of hats are displayed.

[Please no points for *this* response. You can set them to "N/A".]

Re: Daylight saving time

SHABU KHAN — Fri, 05 Apr 2002 19:21:57 GMT

Hi,

This is for Harry and others, a decent link about Daylight Saving Time...

http://webexhibits.org/daylightsaving/b.html

N/A for this one please..

Thanks,
Shabu