Computer time

If you run any kind of a server having the correct time set on the box is helpful for ensuring that items like log entries and emails are dated correctly. Even on a workstation, it's preferable to have the correct time. Often, a computer's clock will gain or lose time and you need to keep resetting it, which is a pain in the neck.

Thankfully, it's easy to automate this. Network Time Protocol provides a way to have your computer automatically keep its clock in sync with an authoritative clock, by polling an NTP server. Here in the US there are a number of publicly-accessible NTP servers. I have my machines set to access a server run by NIST, the National Institute for Standards and Technology. The page for the NIST Internet Time Service is here. On that page, NIST gives you info about NTP and links to NTP clients for Windows machines. It also provides info about how to use NTP from a Mac.

Pretty much all Unix and Unix-like OSes include an NTP client. For example, SUSE Linux includes xntp, which can be configured through YaST to start at bootup and poll an NTP server.