Universal time is approximately the same as Greenwich Mean Time (GMT). Like GMT UT does not include daylight saving changes. The US Naval Observatory has more information about universal time.
Greenwich Mean Time (GMT). Time referred to the zero meridian of longitude (through Greenwich, UK). 0000 UT is local midnight at Greenwich. For example, 00 UT = 10 am Australian EST = 8 am Australian WST = 9.30 am Australian CST.
Standard time at the Prime Meridian passing through Greenwich, England. Also called Coordinated Universal Time, because it is an average of the time kept by atomic clocks in various countries.