Coordinated Universal TimeIn 1972, Coordinated Universal Time (UTC) was adopted worldwide. UTC is determined from six primary atomic clocks that are coordinated by the International Bureau of Weights and Measures located in France. The abbreviation - UTC - was chosen as an international compromise between the initials of the English language form “coordinated universal time” and the French “temps universel coordonné.” Time zone boundaries as used by nations are drawn according to political considerations. Leap seconds are added to UTC periodically, about once each 18 months, so the highly accurate atomic clock time matches the time measured by Earth's rotation, which is very slightly variable due to tidal forces with the Moon.«[Image: some of the world's time zones shown relative to UTC.] |
