Coordinated Universal Time, the official measure of time in the world, it is independent from the time zones UTC time flows like the International Atomic Time (TAI) , except for the insertion of the leap seconds
The accepted abbreviation for "Universal Coordinated Time " This is standard time in Greenwich, England, which is used as a reference time for day and date calculations See also "Epoch" and "GMT "
Co-ordinated Universal Time Universal Time co-ordinated with ephemeris time, i e the rate is defined relative to atomic clock rate but the epoch is defined relative to Universal Time UTC is defined such that it differs from International Atomic Time (IAT) by an exact whole number of seconds The difference can be modified in whole 1-sec increments to keep UTC in agreement with the time defined by the rotation of the Earth to better than 0 9 sec See also atomic time and leap second
Universal Time Coordinated, previously known as Greenwich Mean Time (GMT; 1928 - 1972) UTC was introduced in 1972 and replaces midnight GMT with 0000h (0 hours)
Coordinated Universal Time A time-scale which forms the basis of a coordinated dissemination of standard frequencies and time signals throughout the world