why does my server date keep getting changed?

[lethal0r]

im a moderately skilled linux user, with a debian 3.1 server with directadmin on it. something thats bugging me is that every few days my server date will get set to an hour ahead of what I have set it to. the minutes also appear to go slower - as I check now it it is about 55 minutes ahead of the correct time. the server works fine, it never goes down or anything.

im not sure if theres a script setting the time or something, does anyone know what could be going on here? or a way to check for something that could be setting the date?

[thedondj]

Hi,

You probably have ntpd running on your system. ntpd will constantly synchronise your server's clock with a central clock source. It will do this by running the clock slowly when the clock is fast or running it fast when the clock is slow. This prevents big jumps in clock time which can cause inconsistencies in the filesystem.

If the server is changing it away from the time you have set then you probably have your timezone set incorrectly and the best solution would be to correct the timezone rather than disabling ntp. Alternatively if you are intentionally keeping your timezone different to the reference clocks you may want to disable ntp.

I think you can change the timezone by editing /etc/timezone to one of the paths in /usr/share/zoneinfo, i.e. my timezone file has Europe/London which uses the timezone data from /usr/share/zoneinfo/Europe/London. This howto suggests using tzconfig though.
Debian GNU/Linux System Administrator's Manual - Time

Alternatively you can stop ntp and allow your system to maintain it's own clock at whatever you set it:

sudo /etc/init.d/ntpd stop
sudo rm /etc/rc3.d/S*ntpd

There are situations though where it helps to have your clock synchronised with other systems.

[lethal0r]

thanks for the help. im not sure I understand part of that page:

To change the computer to use UTC after installation, edit the file /etc/default/rcS, change the variable UTC to no. If you happened to install your system to use local time, just change the variable to yes to start using UTC. It is best to reboot after editing /etc/default/rcS to get the changes effective.

it appears to say setting UTC to either yes or no will turn on UTC.

It was set to no, but I changed it to yes and rebooted, however the date still shows the same.

[lugoteehalt]

To sound a bit geeky: the hwclock manual is very interesting.