Universal Time (UT) is a time standard based on the rotation of the Earth. It is a modern continuation of Greenwich Mean Time (GMT), i.e., the mean solar time on the Prime Meridian at Greenwich, and GMT is sometimes used loosely as a synonym for UTC. In fact, the expression "Universal Time" is ambiguous, as there are several versions of it, the most commonly used being UTC and UT1 (see below). All of these versions of UT are based on the rotation of the Earth in relation to distant celestial objects (stars and quasars), but with a scaling factor and other adjustments to make them closer to solar time.
Read more about Universal Time: Universal Time and Standard Time, Measurement, Versions
Famous quotes containing the words universal and/or time:
“We can most safely achieve truly universal tolerance when we respect that which is characteristic in the individual and in nations, clinging, though, to the conviction that the truly meritorious is unique by belonging to all of mankind.”
—Johann Wolfgang Von Goethe (1749–1832)
“When at leisure make preparations for a time of need.”
—Chinese proverb.