Asked by: David King, Wymondham, Norfolk
Most computers today use the Network Time Protocol (NTP) to set their clocks. NTP is a special set of rules for communicating between computers over the internet, designed to synchronise clocks to the Coordinated Universal Time (UTC).
It takes time for messages to travel over the internet, so NTP takes this delay into account when computers are communicating the time with one another. In operation since 1985, NTP is one of the longest running, continuously operating, internet protocols.