"The Network Time Protocol (NTP) is a protocol for synchronizing the clocks of computer systems over packet-switched, variable-latency data networks. NTP uses UDP port 123 as its transport layer. It is designed particularly to resist the effects of variable latency (Jitter).
"Using NTP is a great way to keep your system clock set correctly. It works by contacting a number of servers around the world, asking them for the time and then calculating what the correct local time is from their responses..."
