It depends largely on what you want. I run an ntp server for the pool. Originally installed for my webserver but I have spare bandwidth so decided to "volunteer" my server to pool.ntp.org. If you wish to maintain a reasonably accurate time then install the ntp server package. The ntp.conf is normally installed in /etc . Edit the ntp.conf file and add the following lines to the file;
The drift file allows your system to calculate the error of your system time chip and then apply a correction. The links to the pool servers will allow your system to compare its time to a fairly accurate server and thereby keep an accurate time. Using 3 different servers allows the system to connect to one with the best time and ignore those issuing a bad time (known as a false ticker).