The Network Time Protocol (NTP) is a protocol for synchronizing the clocks of computer systems over packet-switched, variable-latency data networks.
If you only wish to synchronize your clock when the machine boots up, you can use ntpdate. This may be appropriate for some desktop machines which are frequently rebooted, but for servers you should run ntpd.
1. Clock Synchronization using ntpdate
Using ntpdate at boot time is also a good idea for machines that run ntpd. The ntpd program changes the clock gradually, whereas ntpdate sets the clock, no matter how great the difference between a machine's current clock setting and the correct time.Print This Post