Universal Time Coordinated (UTC)

[Boo Boo]

Is UTC the same as Grenwich Mean Time (GMT)?

[kempie]

GMT now usually means the civil (atomic-second based) time kept in the United Kingdom which is the standard time of the time zone centred on the 0 degree meridian. In this (the most common) usage, the terms GMT and UTC are identical.

However in astronavigation GMT can also imply UT1, time based on the Earth's rotation, differing by up to 0.9 seconds from UTC, so the term GMT should not be used for precise purposes -- particularly not in reference to GPS observations.

http://www.apparent-wind.com/gmt-explained.htm l

http://en.wikipedia.org/wiki/UT1

[trevHCS]

Unless you have a physics degree then yes. I suspect the rest of the world got a bit upset (especially the French) at calling it GMT so UTC was invented to keep the peace.

Trev