Server time can be set with ntpdate command on both Linux and FreeBSD.
ntpdate command get date and time from the time server (a server running NTP – Network Time Protocol server) and update the date and time.
Windows by default uses NTP to synchronise time. If you are on Windows 2003 server (not sure about other versions as i use Windows 2003), you can double click time on system tray, then Internet Time to update time from NTP servers.
On Linux/FreeBSD you can do it with following command
freebsd# ntpdate time.nist.gov
2 Nov 08:00:31 ntpdate: step time server 188.8.131.52 offset 19792.770584 sec
You can set time zone with command
Cpanel runs an NTP server for updating time on servers using cpanel control panel.