Table of Contents
64 relations: Accuracy and precision, Astronomical day, Barycentric Dynamical Time, Chatham Islands, Chatham Standard Time Zone, Civil time, Clock, Coordinated Universal Time, DUT1, Earth orientation parameters, Earth's rotation, Ephemeris time, Eucla, Western Australia, General relativity, Great Western Railway, Greenwich, Greenwich Mean Time, International Astronomical Union, International Atomic Time, International Celestial Reference System and its realizations, International Earth Rotation and Reference Systems Service, International Meridian Conference, International System of Units, International Telecommunication Union, International Terrestrial Reference System and Frame, International Time Bureau, Jet Propulsion Laboratory, Julian day, Leap second, List of international common standards, Map, Marine chronometer, Moon, Nautical chart, Nepal Standard Time, Newton's laws of motion, Ohio State University, Planet, Polar motion, Prime meridian, Prime meridian (Greenwich), Quasar, Radar, Rail transport in Great Britain, Royal Navy, Royal Observatory, Greenwich, Sidereal time, Solar time, Standard time, Standard Time Act, ... Expand index (14 more) »
- Time scales
Accuracy and precision
Accuracy and precision are two measures of observational error.
See Universal Time and Accuracy and precision
Astronomical day
An astronomical day refers to a length of day of exactly or nearly 24 hours beginning at noon instead of at midnight. Universal Time and astronomical day are time scales.
See Universal Time and Astronomical day
Barycentric Dynamical Time
Barycentric Dynamical Time (TDB, from the French Temps Dynamique Barycentrique) is a relativistic coordinate time scale, intended for astronomical use as a time standard to take account of time dilation when calculating orbits and astronomical ephemerides of planets, asteroids, comets and interplanetary spacecraft in the Solar System. Universal Time and Barycentric Dynamical Time are time scales.
See Universal Time and Barycentric Dynamical Time
Chatham Islands
The Chatham Islands (Moriori: Rēkohu, 'Misty Sun'; Wharekauri) are an archipelago in the Pacific Ocean about east of New Zealand's South Island, administered as part of New Zealand, and consisting of about 10 islands within an approximate radius, the largest of which are Chatham Island and Pitt Island (''Rangiauria'').
See Universal Time and Chatham Islands
Chatham Standard Time Zone
The Chatham Standard Time Zone is a time zone twelve hours and forty-five minutes ahead of Coordinated Universal Time (UTC) resulting in UTC+12:45.
See Universal Time and Chatham Standard Time Zone
Civil time
In modern usage, civil time refers to statutory time as designated by civilian authorities. Universal Time and civil time are time scales.
See Universal Time and Civil time
Clock
A clock or chronometer is a device that measures and displays time.
Coordinated Universal Time
Coordinated Universal Time (UTC) is the primary time standard globally used to regulate clocks and time. Universal Time and Coordinated Universal Time are time scales.
See Universal Time and Coordinated Universal Time
DUT1
DUT1 (sometimes also written DUT) is a time correction equal to the difference between Universal Time (UT1), which is defined by Earth's rotation, and Coordinated Universal Time (UTC), which is defined by a network of precision atomic clocks. Universal Time and DUT1 are time scales.
Earth orientation parameters
In geodesy and astrometry, earth orientation parameters (EOP) describe irregularities in the rotation of planet Earth.
See Universal Time and Earth orientation parameters
Earth's rotation
Earth's rotation or Earth's spin is the rotation of planet Earth around its own axis, as well as changes in the orientation of the rotation axis in space.
See Universal Time and Earth's rotation
Ephemeris time
The term ephemeris time (often abbreviated ET) can in principle refer to time in association with any ephemeris (itinerary of the trajectory of an astronomical object). Universal Time and ephemeris time are time in astronomy and time scales.
See Universal Time and Ephemeris time
Eucla, Western Australia
Eucla is the easternmost locality in Western Australia, located in the Goldfields-Esperance region of Western Australia along the Eyre Highway, approximately west of the South Australian border.
See Universal Time and Eucla, Western Australia
General relativity
General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics.
See Universal Time and General relativity
Great Western Railway
The Great Western Railway (GWR) was a British railway company that linked London with the southwest, west and West Midlands of England and most of Wales.
See Universal Time and Great Western Railway
Greenwich
Greenwich is a town in south-east London, England, within the ceremonial county of Greater London.
See Universal Time and Greenwich
Greenwich Mean Time
Greenwich Mean Time (GMT) is the local mean time at the Royal Observatory in Greenwich, London, counted from midnight.
See Universal Time and Greenwich Mean Time
International Astronomical Union
The International Astronomical Union (IAU; Union astronomique internationale, UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and development through global cooperation.
See Universal Time and International Astronomical Union
International Atomic Time
International Atomic Time (abbreviated TAI, from its French name temps atomique international) is a high-precision atomic coordinate time standard based on the notional passage of proper time on Earth's geoid. Universal Time and international Atomic Time are time scales.
See Universal Time and International Atomic Time
International Celestial Reference System and its realizations
The International Celestial Reference System (ICRS) is the current standard celestial reference system adopted by the International Astronomical Union (IAU).
See Universal Time and International Celestial Reference System and its realizations
International Earth Rotation and Reference Systems Service
The International Earth Rotation and Reference Systems Service (IERS), formerly the International Earth Rotation Service, is the body responsible for maintaining global time and reference frame standards, notably through its Earth Orientation Parameter (EOP) and International Celestial Reference System (ICRS) groups.
See Universal Time and International Earth Rotation and Reference Systems Service
International Meridian Conference
The International Meridian Conference was a conference held in October 1884 in Washington, D.C., in the United States, to determine a prime meridian for international use.
See Universal Time and International Meridian Conference
International System of Units
The International System of Units, internationally known by the abbreviation SI (from French Système international d'unités), is the modern form of the metric system and the world's most widely used system of measurement.
See Universal Time and International System of Units
International Telecommunication Union
The International Telecommunication Union (ITU)French: Union Internationale des Télécommunications is a specialized agency of the United Nations responsible for many matters related to information and communication technologies.
See Universal Time and International Telecommunication Union
International Terrestrial Reference System and Frame
The International Terrestrial Reference System (ITRS) describes procedures for creating reference frames suitable for use with measurements on or near the Earth's surface.
See Universal Time and International Terrestrial Reference System and Frame
International Time Bureau
The International Time Bureau (Bureau International de l'Heure, abbreviated BIH), seated at the Paris Observatory, was the international bureau responsible for combining different measurements of Universal Time.
See Universal Time and International Time Bureau
Jet Propulsion Laboratory
Jet Propulsion Laboratory (JPL) is a Federally Funded Research and Development Center (FFRDC) in La Cañada Flintridge, California, Crescenta Valley, United States.
See Universal Time and Jet Propulsion Laboratory
Julian day
The Julian day is the continuous count of days since the beginning of the Julian period, and is used primarily by astronomers, and in software for easily calculating elapsed days between two events (e.g. food production date and sell by date). Universal Time and Julian day are time in astronomy.
See Universal Time and Julian day
Leap second
A leap second is a one-second adjustment that is occasionally applied to Coordinated Universal Time (UTC), to accommodate the difference between precise time (International Atomic Time (TAI), as measured by atomic clocks) and imprecise observed solar time (UT1), which varies due to irregularities and long-term slowdown in the Earth's rotation.
See Universal Time and Leap second
List of international common standards
A list of international common and basic technical standards, which have been established worldwide and are related by their frequent and widespread use.
See Universal Time and List of international common standards
Map
A map is a symbolic depiction emphasizing relationships between elements of some space, such as objects, regions, or themes.
Marine chronometer
A marine chronometer is a precision timepiece that is carried on a ship and employed in the determination of the ship's position by celestial navigation.
See Universal Time and Marine chronometer
Moon
The Moon is Earth's only natural satellite.
Nautical chart
A nautical chart or hydrographic chart is a graphic representation of a sea region or water body and adjacent coasts or banks.
See Universal Time and Nautical chart
Nepal Standard Time
Nepal Standard Time (NPT) is the time zone for Nepal.
See Universal Time and Nepal Standard Time
Newton's laws of motion
Newton's laws of motion are three physical laws that describe the relationship between the motion of an object and the forces acting on it.
See Universal Time and Newton's laws of motion
Ohio State University
The Ohio State University (Ohio State or OSU) is a public land-grant research university in Columbus, Ohio, United States.
See Universal Time and Ohio State University
Planet
A planet is a large, rounded astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself.
Polar motion
Polar motion of the Earth is the motion of the Earth's rotational axis relative to its crust.
See Universal Time and Polar motion
Prime meridian
A prime meridian is an arbitrarily-chosen meridian (a line of longitude) in a geographic coordinate system at which longitude is defined to be 0°.
See Universal Time and Prime meridian
Prime meridian (Greenwich)
The Greenwich meridian is a prime meridian, a geographical reference line that passes through the Royal Observatory, Greenwich, in London, England.
See Universal Time and Prime meridian (Greenwich)
Quasar
A quasar is an extremely luminous active galactic nucleus (AGN).
Radar
Radar is a system that uses radio waves to determine the distance (ranging), direction (azimuth and elevation angles), and radial velocity of objects relative to the site.
Rail transport in Great Britain
The railway system in Great Britain is the oldest railway system in the world.
See Universal Time and Rail transport in Great Britain
Royal Navy
The Royal Navy (RN) is the naval warfare force of the United Kingdom, British Overseas Territories and Crown Dependencies, and a component of His Majesty's Naval Service.
See Universal Time and Royal Navy
Royal Observatory, Greenwich
The Royal Observatory, Greenwich (ROG; known as the Old Royal Observatory from 1957 to 1998, when the working Royal Greenwich Observatory, RGO, temporarily moved south from Greenwich to Herstmonceux) is an observatory situated on a hill in Greenwich Park in south east London, overlooking the River Thames to the north.
See Universal Time and Royal Observatory, Greenwich
Sidereal time
Sidereal time ("sidereal" pronounced) is a system of timekeeping used especially by astronomers. Universal Time and Sidereal time are time in astronomy and time scales.
See Universal Time and Sidereal time
Solar time
Solar time is a calculation of the passage of time based on the position of the Sun in the sky. Universal Time and Solar time are time in astronomy and time scales.
See Universal Time and Solar time
Standard time
Standard time is the synchronization of clocks within a geographical region to a single time standard, rather than a local mean time standard. Universal Time and standard time are time scales.
See Universal Time and Standard time
Standard Time Act
The Standard Time Act of 1918, also known as the Calder Act, was the first United States federal law implementing Standard time and Daylight saving time in the United States.
See Universal Time and Standard Time Act
Star
A star is a luminous spheroid of plasma held together by self-gravity.
Sun
The Sun is the star at the center of the Solar System.
Telegraphy
Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message.
See Universal Time and Telegraphy
Terrestrial reference frame
A terrestrial reference frame (TRF) is the reference frame as one views from Earth, or from the surface of another Earth-like planet.
See Universal Time and Terrestrial reference frame
Terrestrial Time
Terrestrial Time (TT) is a modern astronomical time standard defined by the International Astronomical Union, primarily for time-measurements of astronomical observations made from the surface of Earth. Universal Time and Terrestrial Time are time in astronomy and time scales.
See Universal Time and Terrestrial Time
Tidal acceleration
Tidal acceleration is an effect of the tidal forces between an orbiting natural satellite (e.g. the Moon) and the primary planet that it orbits (e.g. Earth).
See Universal Time and Tidal acceleration
Time signal
A time signal is a visible, audible, mechanical, or electronic signal used as a reference to determine the time of day.
See Universal Time and Time signal
Time standard
A time standard is a specification for measuring time: either the rate at which time passes or points in time or both. Universal Time and time standard are time scales.
See Universal Time and Time standard
Timekeeping on Mars
Though no standard exists, numerous calendars and other timekeeping approaches have been proposed for the planet Mars.
See Universal Time and Timekeeping on Mars
Train
A train (from Old French trahiner, from Latin trahere, "to pull, to draw") is a series of connected vehicles that run along a railway track and transport people or freight.
United States Naval Observatory
The United States Naval Observatory (USNO) is a scientific and military facility that produces geopositioning, navigation and timekeeping data for the United States Navy and the United States Department of Defense.
See Universal Time and United States Naval Observatory
Unix time
Current Unix time Unix time is a date and time representation widely used in computing. Universal Time and Unix time are time scales.
See Universal Time and Unix time
Very-long-baseline interferometry
Very-long-baseline interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy.
See Universal Time and Very-long-baseline interferometry
WWV (radio station)
WWV is a shortwave ("high frequency" or HF) radio station, located near Fort Collins, Colorado.
See Universal Time and WWV (radio station)
See also
Time scales
- ΔT (timekeeping)
- Abolition of time zones
- Anti-sidereal time
- Astronomical day
- Barycentric Coordinate Time
- Barycentric Dynamical Time
- Barycentric Julian Date
- Byzantine time
- Civil time
- Coordinate time
- Coordinated Universal Time
- DUT1
- Dynamical time scale
- Ephemeris time
- Geocentric Coordinate Time
- Heliocentric Julian Day
- International Atomic Time
- Local mean time
- Mission Elapsed Time
- Nautical time
- Nuclear timescale
- Railway time
- Sidereal time
- Solar time
- Spacecraft Event Time
- Standard time
- Terrestrial Time
- Thermal time scale
- Time scale
- Time standard
- Time zones
- Universal Time
- Unix time
References
Also known as UT0, UT1, UT1R, UT2, UT2R, UTC-SLS, Universal Standard Time, Universal Time (UT), Universal Time 1.