ALL meanings of universal time
u·ni·ver·sal time
U u - noun Technical meaning of universal time (time, standard) (UT) The mean solar time along the prime meridian (0 longitude) that runs through the Greenwich Observatory outside of London, UK, where the current system originated. UT is tied to the rotation of the Earth in respect to the fictitious "mean Sun". There are three separate definitions, UT0, UT1, and UT2, depending on which corrections have been applied to the Earth's motion. Coordinated Universal Time is kept within 0.9 seconds of UT1, by addition of leap seconds to International Atomic Time. 1
- noun universal time (from 1928) name adopted internationally for Greenwich Mean Time (measured from Greenwich midnight), now split into several slightly different scales, one of which (UT1) is used by astronomers 0
- noun universal time an internationally agreed system for civil timekeeping introduced in 1960 and redefined in 1972 as an atomic timescale. Available from broadcast signals, it has a second equal to the International Atomic Time (TAI) second, the difference between UTC and TAI being an integral number of seconds with leap seconds inserted when necessary to keep it within 0.9 seconds of UT1 0
- noun universal time Greenwich mean time used as a basis for standard time 0