Setting date backwards on HP

[Alpa Shah]

Hi,

While setting the system date backwards on HP m/c it asks me a question.

do you really want to run time backwards?[yes/no]

Is there any switch which can skip this question and change the system date?

I want to use *date* command in perl script and hence want to avoid this question.

Thanks in advance.

[Pete Randall]

The reason the question is asked is because setting the date backwards can have bad consequences for Database servers, where it messes up the re-do logs, causing recovery efforts to be problematic at best.

This little shell script snippet should get you past the response requirement:

echo "yes" > /tmp/yes_time
CTIME=`date +%m%d%H%M%y`
date $CTIME < /tmp/yes_time


Pete

[spex]

# date
Thu Sep 20 08:32:43 EDT 2007
# echo "yes" | date 09200732
date: do you really want to run time backwards?[yes/no]Thu Sep 20 07:32:00 EDT 2007
# date
Thu Sep 20 07:32:02 EDT 2007

PCS

[Alpa Shah]

Thanks a lot.

[Ivan Krastev]

Note that warning from date manual:
The cron daemon should be killed prior to setting the date backwards, then restarted.

regards,
ivan

[Dennis Handly]

I don't think anyone asked why you wanted to set the date backwards. Is this to test DST testing? If so, there are perl scripts to find the beginning and ending times after you install a tztab(4) patch.
See Clay's perl script here:
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1097748

[Alpa Shah]

No, this is something related to licensing.
I want to install a demo license and then want to expire that license by advancing the system date for testing purpose. And then have to set the date back to current date.

Thanks much for the information.

[Bill Hassell]

Setting the date forward and backward for testing should be fine as long as the system has no production applications. But if you have any applications and cron jobs on your system, you can safely assume that there will be a lot of problems, some of which may not be immediately visible.