Daylight Savings Time (DST) Question

[ngoht20]

For OpenVMS 7.1-2 running on Alpha, do I have to set my time to UTC to avoid having to reboot?

Or, do I have to reboot the system even If I set the system to use UTC?

Also, what about local time?? Whats the procedure for DST changes for local time?

I hate having to reboot because I use the system for critical missions...

[John Gillings]

ngoht20,

You can set your time or timezone to whatever you want. All the DST patch does for you is to change it automatically using the modified rules in some timezones. If you're happy to do it manually, and keep track of the rules yourself, you don't need the patch at all (ie: just like you treat your wristwatch, manually updating the time when and if necessary).

You will not need to reboot your system either to install the patch, change the time or change the timezone. Just follow the instructions repeated many times in this forum.

(All this excitement and questions in ITRC over a little thing like a DST definition change! Happens all the time down here)

[ngoht20]

When installing OpenVMS, is the DEFAULT Timezone UTC???

Assuming that during install of VMS, if I do not select my local timezone, will the time setting be defauled as UTC?

[David B Sneddon]

When installing OpenVMS, is the DEFAULT Timezone UTC???

Assuming that during install of VMS, if I do not select my local timezone, will the time setting be defauled as UTC?


You have asked this before and it has been answered.

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1098646

When you install, there is NO DEFAULT.
You choose the timezone.

Dave

[ngoht20]

SO just to confirm ----

SO when I change the time whether its forward during the Spring or backwards during the Fall, I do not have to REBOOT the system and wait 1 hour like I have done when I worked on Mainframes???

Because my friend and my self, have done Mainframe work and whenever we change time for DST, we had to wait 1 hour and then IPL the system...

But for OpenVMS systems, I do not have to IPL the system in order to change for DST time???

[Andy Bustamante]

You do not need to wait an hour or need to reboot when time is changed. That answer applies to the operating system. As far as VMS is concerned, just $ SET TIME (or $ SET TIME/CLUSTER).

If you have a custom application, you may business requirements where an outage may be preferred to out of sequence time stamps. You need to know what application and business rules.

Andy

[ngoht20]

Ok...for example...

Whats the command to change the time ONE HOUR during the Spring??

From lets say 13:00 to 12:00 during the Spring??? Or 12:00 to 13:00 during the Fall??

What command would I do???

[Mobeen_1]

>>>>>>>>>
Whats the command to change the time ONE HOUR during the Spring??
>>>>>>>>>
First check if its a cluster or standalone. To verify this you can do the following command
$show cluster
in the display if you see other systems then its a cluster and use the following command
$ SET TIME/CLUSTER
If it is a standalone node, then use the command below
$SET TIME

>>>>>>>>>
From lets say 13:00 to 12:00 during the Spring??? Or 12:00 to 13:00 during the Fall??
What command would I do???
>>>>>>>>>>
SET TIME=12:00:00.00
SET TIME/CLUSTER=12:00:00.00
use one of the commands @ 13:00 depending on whether your system is clustered or standalone.

regards
Mobeen

[ngoht20]

Thanks...But no REBOOTS are done..right???

Because most Mainframe systems do need to have to be rebooted...

[Nigel Wright_1]

No need to worry about having to reboot - It will just change the time and thats that.

We change the time by the following command file:-

$!
$ set process/privilege=all
$ write sys$output "Time is ",f$time()
$ write sys$output "Setting time forward 1 hour"
$ run sys$system:sysman
set profile/privilege=all
configuration set time "+1"
exit
$ write sys$output "Time is now ",f$time()
$exit

The above is issued as a batch job and the log file created can always be looked at to see what happened.

Note - If you put the time back an hour then a $ anal/disk will come up with errors that files may have dates in the future. But once the time has caught up they will not displayed.

Regards Nigel.

[Sebastian Bazley]

Having the correct timezone setting is important even if you change the time manually.

This is because programs that calculate future and past times need to know when DST changes occur. If the wrong time-zone is set up, then errors may occur around the DST times.

Note that some 3rd party products (Java and Ingres; there are no doubt others) have their own DST definitions so these need to be set up correctly as well.