Coordinated universal time utc clock
UTC is also the time standard used in aviation, e.g. for flight plans and air traffic control clearances.
For sub-microsecond precision, clients can obtain the time from satellite signals. If only limited precision is needed, clients can obtain the current UTC from a number of official Internet UTC servers.
Computer servers, online services and other entities that rely on having a universally accepted time use UTC as it is more specific than GMT. The Network Time Protocol, designed to synchronise the clocks of computers over the Internet, encodes times using the UTC system. UTC is used in many Internet and World Wide Web standards. In 1995, the island nation of Kiribati moved those of its atolls in the Line Islands from UTC-10 to UTC+14 so that the country would all be on the same day. The westernmost time zone uses UTC−12, being twelve hours behind UTC the easternmost time zone, theoretically, uses UTC+12, being twelve hours ahead of UTC. Time zones around the world are expressed using positive or negative offsets from UTC, as in the list of time zones by UTC offset.
The compromise that emerged was UTC, which conforms to the pattern for the abbreviations of the variants of Universal Time (UT0, UT1, UT2, UT1R, etc.). English speakers originally proposed CUT (for "coordinated universal time"), while French speakers proposed TUC (for " temps universel coordonné"). This abbreviation arose from a desire by the International Telecommunication Union and the International Astronomical Union to use the same abbreviation in all languages. The official abbreviation for Coordinated Universal Time is UTC. unofficial French: "Universel Temps Coordonné".unofficial English: "Universal Time Coordinated".See the " Current number of leap seconds" section for the number of leap seconds inserted to date. Leap seconds are inserted as necessary to keep UTC within 0.9 seconds of universal time, UT1. The current version of UTC is defined by International Telecommunications Union Recommendation (ITU-R TF.460-6), Standard-frequency and time-signal emissions and is based on International Atomic Time (TAI) with leap seconds added at irregular intervals to compensate for the slowing of Earth's rotation. A number of proposals have been made to replace UTC with a new system that would eliminate leap seconds but no consensus has yet been reached. The system was adjusted several times until leap seconds were adopted in 1972 to simplify future adjustments. UTC was officially formalized in 1960 by the International Radio Consultative Committee in Recommendation 374, having been initiated by several national time laboratories. For most purposes, UTC is considered interchangeable with GMT, but GMT is no longer precisely defined by the scientific community. It is one of several closely related successors to Greenwich Mean Time (GMT). It is, within about 1 second, mean solar time at 0° longitude it does not observe daylight saving time. Coordinated Universal Time ( French: temps universel coordonné), abbreviated as UTC, is the primary time standard by which the world regulates clocks and time.