The "one-true-way" to synchronize time - NTP

• NTP is the network-time-protocol that adjusts the time in a fluent manner.
• NTP requires a server on one machine, and clients on other machines.
• The clients will measure the time-differences (and the network delays), and will get the clock of the client synchronized with that of the server up to few milli-seconds.
• This process is delicate, and can take several days to stabilize, if the network connection between the machines presents varying delays.
• Now go read The NTP FAQ and HOWTO.

Originally written by guy keren