epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided by ...

is an instant in time chosen as the origin of a particular calendar era. Epoch or EPOCH may also refer to:

Time-related

* Any historical

era An era is a span of time defined for the purposes of chronology or historiography, as in the regnal eras in the history of a given monarchy, a calendar era used for a given calendar, or the geological eras defined for the history of Earth. Comp ...

Epoch (astronomy) In astronomy, an epoch or reference epoch is a moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a celestial body, as they are subject to p ...

, a moment in time used as a reference for the orbital elements of a celestial body *

Epoch (computing) In computing, an epoch is a date and time from which a computer measures system time. Most computer systems determine time as a number representing the seconds removed from particular arbitrary date and time. For instance, Unix and POSIX measure ...

, a moment from which system time is usually measured *

Epoch (cosmology) The timeline of the early universe outlines the formation and subsequent evolution of the Universe from the Big Bang (13.799 ± 0.021 billion years ago) to the present day. An epoch is a moment in time from which nature or situations change to ...

or cosmologic epoch, a phase in the development of the universe since the Big Bang * On the

geologic time scale The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochr ...

, an epoch is a span of time smaller than a period and larger than an age * Epoch (race), racial periods in Blavatsky's esoteric theory of the root races *

Unix epoch Current Unix time () Unix time is a date and time representation widely used in computing. It measures time by the number of seconds that have elapsed since 00:00:00 UTC on 1 January 1970, the beginning of the Unix epoch, less adjustments m ...

, the starting time for Unix-based operating systems

Arts and entertainment

Epoch (DC Comics) Epoch, also known as The Lord of Time, is a comic book fictional character published by DC Comics. He first appeared in ''Justice League of America'' #10 (March 1962) and was created by writer Gardner Fox and artist Mike Sekowsky. A powerful bei ...

, a supervillain also known as the Lord of Time *

Epoch (Marvel Comics) Earth Lord Earth Sentry Earth Sentry (John Foster) was created by Tom DeFalco and Ron Frenz, and first appeared in ''A-Next'' #2 (1999) in the MC2 universe. When John and his father Bill were investigating a UFO crash site, they discovered a ...

, a cosmic entity in the Marvel Comics universe * ''Epoch'' (film), a 2001 American science fiction film * ''Epoch'' (anthology), a 1975 anthology of science fiction stories * ''Epoch'' (video game), a 1981 space combat game for the Apple II * ''Epoch'' (The Brave album), 2016 * ''Epoch'' (Tycho album), 2016 * ''Epoch'', a 2006 album by

Rip Slyme Rip Slyme (often stylized as RIP SLYME) is a Japanese hip hop group. In its best known incarnation, it was primarily composed of four MCs (Ryo-Z, Ilmari, Pes & Su) and a DJ, Fumiya. Pes and Su have since parted ways with the group. Their sou ...

Games

* Epoch Co., a Japanese toy and computer games company **

Epoch Game Pocket Computer The is a second-generation handheld game console released by Epoch Co. in Japan in 1984 for 12,800 Japanese yen. It is also known as ''Pokekon'' and was one of the very few truly handheld systems to be released in the early 1980s, preceding the ...

, an early hand-held game console produced by Epoch Co. * Epoch (Chrono Trigger), a flying time machine in role-playing game ''Chrono Trigger'' * Epoch Hunter, a boss in ''Caverns of Time'' from the game ''

World of Warcraft ''World of Warcraft'' (''WoW'') is a massively multiplayer online role-playing game (MMORPG) released in 2004 by Blizzard Entertainment. Set in the ''Warcraft'' fantasy universe, ''World of Warcraft'' takes place within the world of Azeroth ...

Publications

* ''Epoch'' (American magazine), literary magazine of Cornell University * ''Epoch'' (Russian magazine), literary magazine by Fyodor Dostoyevsky and his brother Mikhail * '' Ha-Tsfira'' (lit. Epoch), a Hebrew language newspaper published in 1862 and 1874–1931 * ''

The Epoch Times ''The Epoch Times'' is a far-right international multi-language newspaper and media company affiliated with the Falun Gong new religious movement. The newspaper, based in New York City, is part of the Epoch Media Group, which also operates New ...

'', a privately owned Falun Gong-linked newspaper

Science and technology

* EPOCH (chemotherapy), a chemotherapy regimen * EPOCh (Extrasolar Planet Observation and Characterization), a NASA mission associated with

EPOXI ''EPOXI'' was a compilation of NASA Discovery program missions led by the University of Maryland and principal investigator Michael A'Hearn, with co-operation from the Jet Propulsion Laboratory and Ball Aerospace. ''EPOXI'' uses the '' Deep Imp ...

* Epoch (machine learning), the complete processing of a (typically large) batch of recorded observations by an

artificial neural network Artificial neural networks (ANNs), usually simply called neural networks (NNs) or neural nets, are computing systems inspired by the biological neural networks that constitute animal brains. An ANN is based on a collection of connected unit ...

Weapons

* Epoch Remote Control Turret