DST CHANGE IN MEXICO

[VICTOR HUGO HERRERA]

Hi.

I have a HP-UX 11.11 system in Mexico that hasn't the PHCO_34668 patch. So I think I don't have to worry at this time, it'll change to CDT on April 1st.

Ideally, this system doesn't need any DST update, but what will happened if a subsequent patch or OS update changes tztab? How should this change be handled in Mexico, where there will be no DST change? Will an entry in tztab be created specifically for countries that don't change DST?

Thanks.

[Pete Randall]

All you have to do is match up what your $TZ variable says to the contents of /usr/lib/tztab. If you have a match, then the rules specified by tztab (see "man tztab") will take effect. Otherwise, you will see no daylight saving time change on any date.


Pete

[VICTOR HUGO HERRERA]

We are in Central Time, so we change to CDT on the first Sunday of April, and back to CST on the last Sunday of October, and we'll continue to do so. This is configured, $TZ and /usr/lib/tztab match:

TZ=CST6CDT

root back1 / # grep CST6CDT /usr/lib/tztab
CST6CDT
CST6CDT#Canada

Thanks.

[OldSchool]

FWIW: The new tztab appears to have added "MST6MXDT" as Mexico City Standard / Daylight Saving Time. Looks like its set to transition TO dst on Sunday in the first week in April, and BACK (to std) Sunday last week of October (like "old" CST rules)

You may want to consider loading the patch and changing the default timezone.

I attached that portion of the file for your review (in theory you could just add it to the existing tztab)

[A. Clay Stephenson]

In your case then you need to set TZ=CST6CDT#Canada
which will result in your desired behavior.

Use the attached perl script to test:

TZ=CST6CDT dst.pl
TZ=CST6CDT#Canada dst.pl

Note that TZ=xxx command has the effect of setting TZ=xxx for just that command.

[VICTOR HUGO HERRERA]

Thanks to all. Is MXST6MXDT in PHCO_34668?
Odd thing is that HP support in Mexico told me that I don't need to do anything.

[A. Clay Stephenson · Accepted solution]

I don't have the tz entry for MXST6MXDT and I have installed PHCO_34342 (but not the intermediate fix PHCO_34668). Note that the reccomended patch is PHCO_36097 but is not yet released but will be before 7-March.

In any event, if you haven't installed PHCO_34342 then you don't have to do anything so HP's advice is correct but shortsighted because as soon as you apply one of the later QualityPacks you are going to get the updated tztab patch and then you will have to deal with it. In any event, you can change your TZ to the xxx#Canada versions and you will be fine with or without the patch.

[James R. Ferguson]

Hi:

> Is MXST6MXDT in PHCO_34668?

No, it's not. But the latest patch for 11.11, PHCO_35989 has the updates for Mexico.

Regards!

...JRF...

[Dennis Handly]

>We are in Central Time ... TZ=CST6CDT

This TZ is reserved for the US.

>Clay: In your case then you need to set TZ=CST6CDT#Canada
which will result in your desired behavior.

How do you and Victor know what politicians Canada will be doing?

The right solution is to use CST6CDT#Mexico
and add entries, or MXST6MXDT.

>Clay: but shortsighted because as soon as you apply one of the later QualityPacks you are going to get the updated tztab patch and then you will have to deal with it.

Exactly, the advice only works NOW and not in the future. But it does give some breathing room.

[OldSchool]

OK, the entry I attached earlier was from the pathces for 11.0. Don't know why they aren't in the 11.11 patch (doesn't really matter).

the correct course of action is to download and install PHCO_35989 which is for 11.11, and set your timezone to CST6CDT#Mexico as noted above.

basically, your going to have to deal w/ it sooner or later, and if you do it now, it won't come back to bite you when subsequent QPs are installed.

Besides, and this may not apply to your situation, its you have remote users logged in that need the US/CST time while you need the Mexico CST time to be the default condition.

[VICTOR HUGO HERRERA]

I applied patch PHCO_35989 and set timezone to CST6CDT#Mexico, then tested with 03/15 and 04/15 and worked fine (all applications down), then back to actual date.

Thanks to everyone.

[VICTOR HUGO HERRERA]

Closing this thread.