This is a really quick post, as most Linux (or M$ Windows) installations will use/need an NTP server to keep the time in sync with other machines on the LAN.
Update and Install
As always, start with an up to date install. Installing the software is just two packages the server, ntp, and some utilities, ntpdate.
sudo apt-get update sudo apt-get dist-upgrade sudo apt-get install ntp ntpdate