Coordinated Universal Time

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coordinated universal time

(UTC) See universal time.

Coordinated Universal Time (UTC)

A time based on the fundamental properties of an atom, the isotope of cesium 133, and not on the movement of heavenly bodies. Atomic time increases at a constant rate, unlike the GMT (Greenwich mean time). This time is corrected for the seasonal variation in the earth's rotation about the sun to bring it within +/−0.1 s of GMT. When the correction reaches +/−0.7 s, a positive or negative leap second is applied to the UTC.

Coordinated Universal Time

(time, standard)
(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 Coordonn?".


The Royal Observatory Greenwich.

History of UTC and GMT.

U.S. National Institute of Standards & Technology.

UK National Physical Laboratory.

US Naval Observatory.

International Telecommunications Union.

Earth's irregular rotation.
References in periodicals archive ?
The ITU World Radiocommunication Conference (WRC-15), currently in session in Geneva from 2 to 27 November, has decided that further studies are required on the impact and application of a future reference time-scale, including the modification of coordinated universal time (UTC) and suppressing the so-called leap second .
The result is Coordinated Universal Time or UTC, the system by which all the world's clocks are set.
The signatures and time stamps provided by nCipher's Time Stamp Server (TSS) bind the documents and the information they contain to a secure official Coordinated Universal Time (UTC) source verified by the Belgium National Measurement Institute (NMI) which is impossible to falsify.
The ACES experiment payload will also help improve the precision and long-term stability of international atomic time (TAI) and coordinated universal time (UTC).
A section about mutual phenomena of the Galilean satellites reads: "It is absolutely essential to record the different phases of the phenomena in Coordinated Universal Time (UTC).
NetWarrior probes are synchronized via QoSmetricseIU patented timing scheme using Coordinated Universal Time (UTC) for increasingly accurate real-time reporting results.
At the heart of the matter is the proposal to abolish the so-called leap second to adjust to the earth s rotation in relation to Coordinated Universal Time (UTC), the current standard for measuring time.
The actual time in the StampServer originates from an official and trusted source of Coordinated Universal Time (UTC) over a secure communications link.
ITU experts and membership along with other organizations have been studying the consequences of eliminating the so-called leap second to adjust to the earth s rotation in relation to Coordinated Universal Time (UTC), the current standard for measuring time.
SymmTime offers the user a number of official time sources from which to download Coordinated Universal Time (UTC) - the international standard for time.
Intercontinental's platform applies a time stamp to every transaction, synchronized to the atomic clock at the Coordinated Universal Time -- which will now be used to automatically detect such trades and prevent their inclusion in Intercontinental's published indices and settlement prices.

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