COHERENT manpages
This page displays the COHERENT manpage for GMT [Definition].
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GMT -- Definition GMT is an abbreviation of Greenwich Mean Time, the time recorded at the Greenwich Observatory in England, where by international convention the Earth's zero meridian is fixed. By definition, COHERENT fixes system time in GMT. It calculates local time as an offset of GMT; for example, the time zone for Chicago is six hours (360 minutes) behind Greenwich, so the local time for Chicago is calculated by subtracting 360 minutes from GMT. See Also gmtime(), localtime, Programming COHERENT, time, time.h, TIMEZONE Notes The ANSI Standard replaces GMT with UTC (universel temps coordonne or universal coordinated time) for C programming. The change is mainly one of terminology rather than substance, as some signatories to international conventions object to naming the standard for global time after a suburb of London. Under international convention, there are two UTC standards: UTC1 is based on solar time and is identical to current GMT; and UTC2, which uses atomic clocks that are corrected by comparison with pulsars. These standards drift apart as the earth's rotation slows; thus, ``leap seconds'' are inserted periodically into UTC1 to bridge the difference.