(Transferred from the wiki by Peter)
This was posted by Otheos at www.techimo.com and he kindly gave me permision to reprint it here
The first thing you need to do is make sure the package rdate is installed, there are packages for both debain and redhat based systems.
Next you need a time server that has accurate time.
time.nrc.ca is a good one
Then you need one box to get the time from this server:
Then you need your other boxes to read the time from your local server:
rdate -s time.nrc.ca
or you can set each box to do it directly from outside. You can do it once in boot time, or make a cron job for it in the root users crontab. To do this type as user root crontab -e in a terminal and then enter
rdate -s myserver where myserver is the Linux machine you just set the time to.
This will sync the computer at the start of every hour.
0 * * * * /usr/bin/rdate -s time.nrc.ca
Finally if you run samba on your local server you can have your windows boxes setting their time from it by adding:
under the [global] in your smb.conf and then from your windows boxes (w2k, sorry this is what I know/use) do from the cli:
You can make a shortcut to it and add it in your startup.
net time \\myserver /set /yes
Now all your boxes have the same time