Clock · Horology · History of timekeeping devices · Astrarium · Marine chronometer · Sundial · Water clock
Wikipedia does not have an article with this exact name. ... Wiktionary (a portmanteau of wiki and dictionary) is a multilingual, Web-based project to create a free content dictionary, available in over 151 languages. ... This article is about the concept of time. ... This article is about the concept of time. ... While in the popular mind, eternity often simply means existing for an infinite, i. ... Arguments for eternity composed a particularly important area of philosophical debate among Greek, Jewish, Islamic, and Christian philosophers during the ancient and medieval periods. ... The Fountain of Eternal Life in Cleveland, Ohio Immortality (or eternal life) is the concept of living in physical or spiritual form for an infinite length of time, or in a state of timelessness. ... Deep time is the theory that Earth is billions of years old and thus had a long history of development and change. ... This article is about the study of the past in human terms. ... The past is the portion of the timeline that has already occurred; it is the opposite of the future. ... Present redirects here. ... For other uses, see Future (disambiguation). ... Futurology is the detailed critical inspection and reasoning of the state in which things will develop in the future on the basis of existing circumstances in history. ... Image File history File links Portal. ... A time scale specifies divisions of time. ... Wikipedia does not yet have an article with this exact name. ... UTC redirects here. ... Universal Time (UT) is a timescale based on the rotation of the Earth. ... International Atomic Time (TAI, from the French name Temps Atomique International) is a high-precision atomic time standard that tracks proper time on Earths geoid. ... This article is about the unit of time. ... A minute is a unit of time equal to 1/60th of an hour and to 60 seconds. ... The hour (symbol: h) is a unit of time. ... Sidereal time is time measured by the apparent diurnal motion of the vernal equinox, which is very close to, but not identical with, the motion of stars. ... Solar time is based on the idea that when the sun reaches its highest point in the sky, it is noon. ... Timezone and TimeZone redirect here. ... For other uses, see Clock (disambiguation). ... Horology is the study of the science and art of timekeeping devices. ... An astrarium, also called a planetarium, is the mechanical representation of the cyclic nature of astronomical objects in one timepiece. ... A marine chronometer is a timekeeper precise enough to be used as a portable time standard, used to determine longitude by means of celestial navigation. ... For other uses, see Sundial (disambiguation). ... A water clock or clepsydra is a device for measuring time by letting water regularly flow out of a container usually by a tiny aperture. ...

Calendar · Day · Week · Month · Year · Tropical year · Julian · Gregorian · Islamic
For other uses, see Calendar (disambiguation) A page from the Hindu calendar 1871–1872. ... Look up day in Wiktionary, the free dictionary. ... For more details on each day of the week, see days of the week. ... Look up Month in Wiktionary, the free dictionary. ... A year (from Old English gēr) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... A tropical year is the length of time that the Sun, as viewed from the Earth, takes to return to the same position along the ecliptic (its path among the stars on the celestial sphere). ... The Julian calendar was a reform of the Roman calendar which was introduced by Julius Caesar in 46 BC and came into force in 45 BC (709 ab urbe condita). ... For the calendar of religious holidays and periods, see liturgical year. ... The Islamic calendar or Muslim calendar (Arabic: التقويم الهجري; at-taqwīm al-hijrī; Persian: تقویم هجري قمری ‎ taqwīm-e hejri-ye qamari; also called the Hijri calendar) is the calendar used to date events in many predominantly Muslim countries, and used by Muslims everywhere to determine the proper day on which to celebrate...

Arrow of time · Chronon · Fourth dimension · Planck epoch · Planck time · Time domain
Intercalation is the insertioffn of an extra day, week or month into some calendar years to make the calendar follow the seasons. ... A leap second is a one-second adjustment to civil time in order to keep it close to the mean solar time. ... For the 1921 film starring Fatty Arbuckle, see Leap Year (film). ... For the novel by Michael Crichton, see Timeline (novel). ... Diagram of geological time scale. ... Geological time scale. ... Geochronology is the science of determining the age of rocks, fossils, and sediments. ... Dating material drawn from the archaeological record can made by a direct study of a artifact or may be deduced by association with materials found in the context the item is drawn from or inferred by its point of discovery in the sequence relative to datable contexts. ... A calendar era is the year numbering system used by a calendar. ... Regnal year: the year of the reign of a sovereign. ... Generally a chronicle (Latin chronica, from Greek Χρόνος) is historical account of facts and events in chronological order. ... Periodization is the attempt to categorize or divide time into discrete named blocks. ... Wheel of time may refer to: The Wheel of time or history, a religious concept predominant in Buddhism and Hinduism The Wheel of Time, a fantasy book series by author Robert Jordan The Wheel of Time (computer game), an action first-person shooter based on the series The Timewheel, a... is the Sanskrit for time (from a root to enumerate; unrelated to black whence ). It denotes a fixed or right point in time (compare rtu, kairos). ... Kālacakra (Sanskrit कालचक्र; Tibetan དུས་ཀྱི་འཁོར་ལོ་ dus kyi khor lo) is a term used in Tantric Buddhism that means time-wheel or time-cycles. It refers both to a Tantric deity (Tib. ... For other uses, see Prophecy (disambiguation). ... opens chapter nine of The Dreaming Universe (1994) entitled The Dreamtime with a quote from The Last Wave, a film by Peter Weir: Aboriginals believe in two forms of time. ... Philosophy of space and time is the branch of philosophy concerned with the issues surrounding the ontology, epistemology, and character of space and time. ... Causality or causation denotes the relationship between one event (called cause) and another event (called effect) which is the consequence (result) of the first. ... Eternalism is a philosophical approach to the ontological nature of time. ... Eternal return or sometimes eternal recurrence is a concept originating from ancient Egypt and developed in the teachings of Pythagoras. ... This page is a candidate for speedy deletion because: this page is a test If you disagree with its speedy deletion, please explain why on its talk page or at Wikipedia:Speedy deletions. ... Wikisource has original text related to this article: The Unreality of Time To meet Wikipedias quality standards, this article or section may require cleanup. ... A-series and B-series are terms introduced by the Scottish idealist philosopher John McTaggart in 1908 which have become classic terms of reference in modern discussions of the philosophy of time, even outside the analytic tradition. ... The B-theory of time is a term, given to one a two positions taken by theorists, in the philosophy of time. ... This article or section is in need of attention from an expert on the subject. ... In the philosophy of time, four dimensionalism is the view that reality is a four-dimensional continuum composed of time and space (spacetime). ... Perdurantism or perdurance theory is a philosophical theory of persistence and identity. ... In the philosophy of time, presentism is the belief that neither the future nor the past exists. ... Temporal Parts are used in contemporary metaphysics in the debate over persistence of material objects. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... For other uses of this term, see Spacetime (disambiguation). ... In physics, the concept of absolute time and absolute space are hypothetical models in which time either runs at the same rate for all the observers in the universe or the rate of time of each observer can be scaled to the absolute time by multiplying the rate by a... T-symmetry is the symmetry of physical laws under a time-reversal transformation— The universe is not symmetric under time reversal, although in restricted contexts one may find this symmetry. ... This article or section does not cite its references or sources. ... A chronon is a hypothetical concept in theoretical physics intended to describe a quantum of time. ... For other uses, see Fourth dimension (disambiguation). ... Named after Max Planck, in cosmology the Planck epoch (or Planck Era) is the earliest period of time in the history of the universe, from zero to 10-43 seconds (one Planck time), during which all four fundamental forces were unified and elementary particles did not yet exist. ... In physics, the Planck time (tP), is the unit of time in the system of natural units known as Planck units. ... Time-domain is a term used to describe the analysis of mathematical functions, or real-life signals, with respect to time. ...

Egyptian · Sothic cycle · Hindu units of measurement · Vedic time-cycles
Two-dimensional analogy of space-time curvature described in General Relativity. ... Time dilation is the phenomenon whereby an observer finds that anothers clock which is physically identical to their own is ticking at a slower rate as measured by their own clock. ... Gravitational time dilation is a consequence of Albert Einsteins theories of relativity and related theories which causes time to pass at different rates in regions of a different gravitational potential; the higher the local distortion of spacetime due to gravity, the slower time passes. ... Coordinate time is the interval of time independent of relativistic time dilation. ... In relativity, proper time is time measured by a single clock between events that occur at the same place as the clock. ... Space-time theories of consciousness relate the geometrical features of conscious experience, such as viewing things in space-time at a point, to the geometrical properties of the universe itself. ... // Definition and history Psychologists have investigated mental chronometry for over 100 years. ... Reaction time (RT) is the elapsed time between the presentation of a sensory stimulus and the subsequent behavioral response. ... Although the sense of time is not associated with a specific sensory system, the work of psychologists and neuroscientists indicates that our brains do have a system governing the perception of time. ... The specious present is the time duration wherein ones perceptions are considered to be in the present. ... Future studies reflects on how today’s changes (or the lack thereof) become tomorrow’s reality. ... The Long Now Foundation, established in 1996, is a private organization that seeks to become the seed of a very long-term cultural institution. ... In sociology and anthropology, time discipline is the general name given to social and economic rules, conventions, customs, and expectations governing the measurement of time, the social currency and awareness of time measurements, and peoples expectations concerning the observance of these customs by others. ... The time value of money is the premise that an investor prefers to receive a payment of a fixed amount of money today, rather than an equal amount in the future, all else being equal. ... This article is about the idea of space. ... A duration is an amount of time or a particular time interval. ... For other uses, see Time capsule (disambiguation). ... Time travel is a concept that has long fascinated humanity—whether it is Merlin experiencing time backwards, or religious traditions like Mohammeds trip to Jerusalem and ascent to heaven, returning before a glass knocked over had spilt its contents. ... The time signature (also known as meter signature) is a notational convention used in Western musical notation to specify how many beats are in each measure and what note value constitutes one beat. ... In computer science and computer programming, system time represents a computer systems notion of the passing of time. ... For other uses, see Carpe diem (disambiguation). ... Tempus fugit on a sundial Tempus fugit is a Latin expression meaning time flees, more commonly translated as time flies. It is frequently used as an inscription on clocks. ... For the novel by Michael Crichton, see Timeline (novel). ... This article is about the concept of time. ... For other uses, see Astronomy (disambiguation). ... This article includes a list of works cited but its sources remain unclear because it lacks in-text citations. ... Paleontology, palaeontology or palæontology (from Greek: paleo, ancient; ontos, being; and logos, knowledge) is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. ... For referencing in Wikipedia, see Wikipedia:Citing sources. ... This article is about the study of the past in human terms. ... Image File history File links Download high resolution version (800x697, 123 KB) fr:: Montre gousset cs:: Kapesní hodinky de: Deutsch: Taschenuhr en: English: Pocket watch it: Italiano: Orologio da taschino (cipolla) es: Español: Reloj de bolsillo Template:ગુજરાતી ગુજરાતી: ખિસ્સામાં રાખવાની ઘડિયાળ ja: 日本語: 懐中時計 pl: Polski: Zegarek kieszonkowy pt: Português: Relógio de bolso... Image File history File links Portal. ... An era is a long period of time with different technical and colloquial meanings, and usages in language. ... In chronology, an epoch (or epochal date, or epochal event) means an instant in time chosen as the origin of a particular era. ... A calendar era is the year numbering system used by a calendar. ... Ab urbe condita (related with Anno urbis conditae: AUC or a. ... AD redirects here. ... BCE redirects here. ... Anno Mundi (AM, in the year of the world) refers to a Calendar era counting from the creation of the world. ... The Spanish era or Era of the Caesars refers to the dating system used in Hispania until the fourteenth century and the adoption of Anno Domini. ... Before Present (BP) years are the units of time (counted backwards to the past) used to report raw radiocarbon ages and dates referenced to the BP scale origin in the year AD 1950 (identical to 1950 CE). ... The Islamic calendar or Muslim calendar (Arabic: التقويم الهجري; at-taqwÄ«m al-hijrÄ«; Persian: تقویم هجري قمری ‎ taqwÄ«m-e hejri-ye qamari; also called the Hijri calendar) is the calendar used to date events in many predominantly Muslim countries, and used by Muslims everywhere to determine the proper day on which to celebrate... The Sothic cycle or Canicular period is a period of 1461 ancient Egyptian years (of 365 days) or 1460 Julian years (averaging 365. ... Old Indian measures are still in use today, primarily for religious purposes in Hinduism and Jainism. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

Gregorian · Proleptic Gregorian · Old Style and New Style
Regnal year: the year of the reign of a sovereign. ... The Canon of Kings was a dated list of kings used by ancient astronomers as a convenient means to date astronomical phenomena, such as eclipses. ... Limmu was an Assyrian eponym. ... Coin of Philip V of Macedon (ruled 221–179 BC). ... An era name was assigned as the name of each year by the leader (emperor or king) of the East Asian countries of China, Korea, Japan, and Vietnam during some portion of their history. ... For other uses, see Calendar (disambiguation) A page from the Hindu calendar 1871–1872. ... The Roman calendar changed its form several times in the time between the foundation of Rome and the fall of the Roman Empire. ... The Julian calendar was a reform of the Roman calendar which was introduced by Julius Caesar in 46 BC and came into force in 45 BC (709 ab urbe condita). ... The proleptic Julian calendar is produced by extending the Julian calendar to dates preceding its official introduction in 45 BC. Historians since Bede have traditionally represented the years preceding AD 1 as 1 BC, 2 BC, etc. ... The Revised Julian calendar is a calendar that was considered for adoption by the Eastern Orthodox churches at a synod in Istanbul in May 1923. ... For the calendar of religious holidays and periods, see liturgical year. ... The proleptic Gregorian calendar is produced by extending the Gregorian Calendar to dates preceding its official introduction in 1582. ... Old Style redirects here. ...

Lunisolar · Solar · Lunar · Islamic · Chinese sexagenary cycle
A lunisolar calendar is a calendar whose date indicates both the moon phase and the time of the solar year. ... A solar calendar is a calendar whose dates indicate the position of the earth on its revolution around the sun (or equivalently the apparent position of the sun moving on the celestial sphere). ... A lunar calendar is a calendar that is based on cycles of the moon phase. ... The Islamic calendar or Muslim calendar (Arabic: التقويم الهجري; at-taqwīm al-hijrī; Persian: تقویم هجري قمری ‎ taqwīm-e hejri-ye qamari; also called the Hijri calendar) is the calendar used to date events in many predominantly Muslim countries, and used by Muslims everywhere to determine the proper day on which to celebrate... The Chinese sexagenary cycle (Chinese: ; pinyin: ) is a cyclic numeral system of 60 combinations of the two basic cycles, the ten Heavenly Stems (天干; tiāngān) and the twelve Earthly Branches (地支; dìzhī). These have been traditionally used as a means of numbering days and years, not only in China...

Absolute dating · Incremental dating · Archaeomagnetic dating · Dendrochronology · Glottochronology · Ice core · Lichenometry · Paleomagnetism · Radiocarbon dating · Radiometric dating · Tephrochronology · Thermoluminescence dating · Uranium-lead dating
Astronomical year numbering is based on BCE/CE (or BC/AD) year numbering, but follows normal decimal integer numbering more strictly. ... The ISO week date system is a leap week calendar system that is part of the ISO 8601 date and time standard. ... An ephemeris (plural: ephemerides) (from the Greek word ephemeros = daily) is a device giving the positions of astronomical objects in the sky. ... // Galactic time NGC 4414, a typical spiral galaxy alike our Milky Way Galactic time, not to confuse with siderial time, is the time that is described by our spin relative to the center of the galaxy. ... The Metonic cycle or Enneadecaeteris in astronomy and calendar studies is a particular approximate common multiple of the year (specifically, the seasonal tropical year) and the synodic month. ... Milankovitch cycles are the collective effect of changes in the Earths movements upon its climate, named after Serbian civil engineer and mathematician Milutin Milanković. The eccentricity, axial tilt, and precession of the Earths orbit vary in several patterns, resulting in 100,000 year ice age cycles of the... Diagram of geological time scale. ... Deep time is the theory that Earth is billions of years old and thus had a long history of development and change. ... Geological time scale. ... In general usage, an eon (sometimes spelled æon) is an arbitrarily designated period of time. ... A geologic era is a subdivision of geologic time that is a separate classification that divides the Phanerozoic Eon into three parts timeframes. ... A geologic period is a subdivision of geologic time that divides an era into smaller timeframes. ... Faunal stages are a subdivision of geologic time used primarily by paleontologists who study fossils rather than by geologists who study rock formations. ... Chronostratigraphy is the branch of stratigraphy that studies the age of rock strata in relation to time. ... Geochronology is the science of determining the age of rocks, fossils, and sediments. ... Isotope geochemistry is an aspect of Geology based upon study of the relative and absolute concentrations of the elements and their isotopes in the Earth. ... See here for the superposition principle of physics. ... Optical dating is a method of determining how long ago minerals were last exposed to daylight. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Dating material drawn from the archaeological record can made by a direct study of a artifact or may be deduced by association with materials found in the context the item is drawn from or inferred by its point of discovery in the sequence relative to datable contexts. ... Absolute dating is the process of determining a specific archaeological date. ... Incremental dating techniques allow the construction of year-by-year annual chronologies, which can be fixed ( linked to the present day and thus calendar or sidereal time) or floating. ... Archaeomagnetism (adjective archaeomagnetic) is the science of how to interpret signatures of the Earths magnetic field at past times that are recorded in archaeological materials. ... The growth rings of an unknown tree species, at Bristol Zoo, England Pinus taeda Cross section showing annual rings, Cheraw, South Carolina Pine stump showing growth rings Dendrochronology or tree-ring dating is the method of scientific dating based on the analysis of tree-ring growth patterns. ... Glottochronology refers to methods in historical linguistics used to estimate the time at which languages diverged, based on the assumption that the basic (core) vocabulary of a language changes at a constant average rate. ... Ice Core sample taken from drill. ... Lichens are a symbiotic relationship between algal and fungal communities and they increase in size radially as they grow. ... Paleomagnetism refers to the study of the record of the Earths magnetic field preserved in various magnetic minerals through time. ... Radiocarbon dating is a radiometric dating method that uses the naturally occurring isotope carbon-14 (14C) to determine the age of carbonaceous materials up to about 60,000 years. ... Radiometric dating (often called radioactive dating) is a technique used to date materials, based on a comparison between the observed abundance of particular naturally occurring radioactive isotopes and their known decay rates. ... Tephrochronology is a geochronolgical technique that utilises discreet layers of tephra—volcanic ash from a single eruption— to create a chronological framework in which palaeoenvironmental or archaeological records can be placed. ... Thermoluminescence (TL) dating is the determination by means of measuring the accumulated radiation dose of the time elapsed since material containing crystalline minerals was either heated (lava, ceramics) or exposed to sunlight (sediments). ... Radiometric dating is a technique used to date materials based on a knowledge of the decay rates of naturally occurring isotopes, and the current abundances. ...