[ntp:questions] different times from same ntp server

[ntp:questions] different times from same ntp server

Post by Metal Gea » Fri, 27 May 2005 18:22:31

My timezone configuration is correctly set i.e. Asia/Karachi and only one
possibility is left that OS's timezone definitions, now how can i correct
that definitions.


[ntp:questions] different times from same ntp server

Post by Tapio Soku » Sun, 29 May 2005 00:24:24

Looks like Pakistan had daylight saving time in 2002, but not after
that anymore. Probably your timezone definition files are last
updated in 2002 and therefore think that daylight saving time should
still be observed.

To fix this you need to update the timezone definition file. To do
that copy the lines at the bottom of this message to a temporary
file and as root say "zic filename", which reads the file and
converts it to a compiled timezone file and installs it for you
(the final location is probably /usr/share/zoneinfo/Asia/Karachi).
And to be sure, after running the zic-command, reselect your
timezone with your OS's timezone selection utility.

Make sure you copy all lines below and that they don't wrap to
the following line. It doesn't matter if the amount of whitespace
within a line changes, as long as there is at least one
space between each item on a line. There should be 10 lines in
the resulting file. If the rules change again, you can get
updated timezone information from
http://www.yqcomputer.com/ (this is from there).

Rule Pakistan 2002 only - Apr Sun>=2 0:01 1:00 S
Rule Pakistan 2002 only - Oct Sun>=2 0:01 0 -
Zone Asia/Karachi 4:28:12 - LMT 1907
5:30 - IST 1942 Sep
5:30 1:00 IST 1945 Oct 15
5:30 - IST 1951 Sep 30
5:00 - KART 1971 Mar 26 # Karachi Time
5:00 Pakistan PK%sT # Pakistan Time


[ntp:questions] different times from same ntp server

Post by Metal Gea » Tue, 31 May 2005 14:06:32

Thanks for the help,
i exactly did what u said copying the lines and running zic command all went
fine. Now when i run date command i m shown the exact date and time but in
system tray i m shown the one hour ahead of the local time is there any
solution for that. One other question is that should i check 'System clock
uses UTC' or not. I m using REdhat 9.


[ntp:questions] different times from same ntp server

Post by Metal Gea » Tue, 31 May 2005 15:32:46

After 30 mins the tray icon also started to give the correct time (any idea
why it was too late to update).

[ntp:questions] different times from same ntp server

Post by Tapio Soku » Tue, 31 May 2005 21:39:54

I'd say it is mostly a matter of personal preference. On machines that
only run linux I usually keep the system clock in UTC. One advantage of
keeping the clock in UTC is that the time is never ambiguous, which is
possible if the timezone is not UTC and observes summer time. A system
clock doesn't store the timezone/UTC offset information, so when booting
it can't tell the OS whether the switch to daylight saving time has or
has not been done.


[ntp:questions] different times from same ntp server

Post by Brad Knowl » Tue, 31 May 2005 21:50:24

If you're managing more than one machine, then keeping all your
systems in UTC makes it much easier to correlate events from one
machine to another, by looking in their log files (i.e., some event
happened on one machine at such-and-such time, so what was happening
on the other machine around that time?). It also makes it much
easier to immediately see if the clocks are way off, because you
don't have to do any time zone calculations in your head.

The only reason (I know of) that you might want to run your
systems in any timezone other than UTC is if those darn pesky humans
come into the equation and they're confused when the clock says that
the time is 12:46PM when you know it's actually late afternoon.

That problem can be fixed by running the system clock in UTC, but
having individual users set their timezone preference within their
login scripts, etc....

Brad Knowles, < XXXX@XXXXX.COM >

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

-- Benjamin Franklin (1706-1790), reply of the Pennsylvania
Assembly to the Governor, November 11, 1755

SAGE member since 1995. See < http://www.yqcomputer.com/ ; for more info.

[ntp:questions] different times from same ntp server

Post by Richard B. » Tue, 31 May 2005 22:36:43

It looks to me as if you are having Linux problems, not NTP problems.
Your system is keeping the correct time, just displaying an incorrect
offset in one place. A Linux group is probably a better place to look
for help.