Change in Mongolian daylight saving time
eggert at twinsun.com
Sat Apr 17 09:29:58 UTC 2004
At Sat, 17 Apr 2004 16:15:51 +0900, Ganbold <ganbold at micom.mng.net> writes:
> One more question, maybe this is off topic. How to make time
> synchronization? I installed ntp daemon which makes synchronization
> from some public time servers. However because of daylight saving
> time it is still off by 1 hour.
Most likely, NTP is working correctly; it is merely your zoneinfo
data that are wrong.
You can test this by using the command "date -u". If "date -u" prints
the correct Universal time, then it's not an NTP problem; it's a
> Can you give me some advice and solution to make time
> synchronization which counts daylight saving?
Assuming NTP is not the problem, here's what I'd do:
1. Obtain the latest zoneinfo data as described in
2. Make the following change to the "asia" file.
-Rule Mongol 2001 only - Apr 27 2:00s 1:00 S
-Rule Mongol 2001 only - Sep 28 2:00s 0 -
+Rule Mongol 2001 only - Apr lastSat 2:00 1:00 S
+Rule Mongol 2001 max - Sep lastSat 2:00 0 -
+Rule Mongol 2002 max - Mar lastSat 2:00 1:00 S
3. Run the command "zic asia". You may also need to give a -d option
to "zic", to match the location of your local configuration.
This should create a file whose name is (say)
4. Set your TZ environment variable to "Asia/Ulaanbaatar".
More information about the tz