> Greenwich Mean Time (GMT), the name for mean solar time of the longitude (0°) of the Royal Greenwich Observatory in England
> ...in 1928 the International Astronomical Union changed the designation of the standard time of the Greenwich meridian to Universal Time. Universal Time remains in general use in a modified form as Coordinated Universal Time (UTC), which serves to accommodate the timekeeping differences that arise between atomic time (derived from atomic clocks) and solar time.
According to Encyclopaedia Britannica:
> Greenwich Mean Time (GMT), the name for mean solar time of the longitude (0°) of the Royal Greenwich Observatory in England
> ...in 1928 the International Astronomical Union changed the designation of the standard time of the Greenwich meridian to Universal Time. Universal Time remains in general use in a modified form as Coordinated Universal Time (UTC), which serves to accommodate the timekeeping differences that arise between atomic time (derived from atomic clocks) and solar time.