coordinated universal time
     n : Greenwich Mean Time updated with leap seconds [syn: UTC]

	

	Coordinated Universal Time
     
         (UTC, World Time) The standard time common to
        every place in the world.  UTC is derived from International
        Atomic Time (TAI) by the addition of a whole number of "leap
        seconds" to synchronise it with Universal Time 1 (UT1), thus
        allowing for the eccentricity of the Earth's orbit, the
        rotational axis tilt (23.5 degrees), but still showing the
        Earth's irregular rotation, on which UT1 is based.
     
        Coordinated Universal Time is expressed using a 24-hour clock
        and uses the Gregorian calendar.  It is used in aeroplane
        and ship navigation, where it also sometimes known by the
        military name, "Zulu time".  "Zulu" in the phonetic alphabet
        stands for "Z" which stands for longitude zero.
     
        UTC was defined by the International Radio Consultative
        Committee (CCIR), a predecessor of the ITU-T.  CCIR
        Recommendation 460-4, or ITU-T Recommendation X.680 (7/94),
        contains the full definition.
     
        The language-independent international abbreviation, UTC, is
        neither English nor French.  It means both "Coordinated
        Universal Time" and "Temps Universel Coordonne".
     
        BIPM
        (http://www.bipm.fr/enus/5_Scientific/c_time/time_1.html).
     
        The Royal Observatory Greenwich
        (http://www.rog.nmm.ac.uk/leaflets/time/time.html).
     
        History of UTC and GMT
        (http://ecco.bsee.swin.edu.au/chronos/GMT-explained.html).
     
        U.S. National Institute of Standards & Technology
        (http://www.its.bldrdoc.gov/fs-1037/dir-009/_1277.htm).
     
        UK National Physical Laboratory
        (http://www.npl.co.uk/npl/ctm/time_scales.html).
     
        US Naval Observatory
        (http://tycho.usno.navy.mil/systime.html).
     
        International Telecommunications Union
        (http://www.itu.int/radioclub/rr/arts02.htm).
     
        Earth's irregular rotation
        (http://www.foldoc.org/pub/earth_rotation).
     
        (2001-08-30)