208 relations: Academic term, Academic year, Accusative case, Age of the universe, Ancient Greek, Anno Domini, Anthropology, Apophony, Apsis, Archaeology, Armenian calendar, Astronomical Almanac, Astronomical year numbering, Astronomy, Australia, Autumn, Avestan, Axial precession, Axial tilt, Aztec calendar, Before Present, Big Bang, Billion years, Boston Latin School, Brunhes–Matuyama reversal, Cadmium, Calendar, Calendar era, Calendar year, Canada, Cardinal number (linguistics), Celestial mechanics, Century, Common Era, Common year, Correlation and dependence, Counting, Cretaceous, Day, Daylight, Decade, Dendrochronology, Dinosaur, Dry season, Earth, Earth's orbit, Eastern Orthodox Church, Eclipse, Eclipse season, Ecliptic, ..., Ecliptic coordinate system, Educational institution, Eemian, Egyptian calendar, Ephemeris day, Ephemeris time, Epoch (astronomy), Epoch (reference date), Eukaryote, February 29, Federal government of the United States, Fiscal year, Friedrich Bessel, Full moon, Galactic Center, Galactic year, Gaussian gravitational constant, Gaussian year, Geological period, Geology, German language, Gothic language, Great Year, Gregorian calendar, Haab', Hebrew calendar, Heliacal rising, Hindu calendar, History of Earth, Holocene, Homo sapiens, Hour, Ice age, Ice core, India, Integer, Intercalation (timekeeping), International Astronomical Union, International System of Quantities, International Union of Geological Sciences, International Union of Pure and Applied Chemistry, Iranian calendars, Islamic holidays, ISO 80000-3, ISO 8601, Jalali calendar, Julian calendar, Julian year (astronomy), Kyr, Last Glacial Maximum, Latin, Latin declension, Leap year, Light-year, List of calendars, List of years, Long and short scales, Lunar calendar, Lunar node, Lunar precession, March equinox, Mesoamerican calendars, Metric prefix, Millennium, Minute, Month, Muslim, Myr, Names of large numbers, Nativity of Jesus, Neolithic Revolution, New Scientist, Nowruz, Old Church Slavonic, Old English, Old High German, Old Norse, Orbit, Orbital period, Orders of magnitude (numbers), Orders of magnitude (time), Oxford English Dictionary, Oxford University Press, Paleontology, Parts-per notation, Pascal (unit), Perihelion and aphelion, Physical cosmology, Physical Review, Planet, Pleistocene, Pliocene, Post-glacial rebound, Precession, Proto-Germanic language, Proto-Indo-European language, Pure and Applied Chemistry, Radiocarbon dating, Ramadan, Recent African origin of modern humans, Red dwarf, Revised Julian calendar, Sanskrit, Sea level rise, Season, Seasonal year, Second, SI base unit, Sidereal year, Sirius, Soil fertility, Solar calendar, Solar Hijri calendar, Solar System, Sothic cycle, Spring (season), Subarctic climate, Subtropics, Summer, Sun, Supermoon, Tantalum, Tehran, Temperate climate, Terrestrial Time, Theropoda, Tidal acceleration, Timekeeping on Mars, Tropical year, Tropics, Tungsten, Tyrannosaurus, Unified Code for Units of Measure, Unit of time, United Kingdom, United Kingdom Hydrographic Office, United States, United States Government Publishing Office, Universal Time, University of Massachusetts Press, Uranium–thorium dating, Varve, Vedic Sanskrit, Vegetation, Venus, Weather, Week, West Saxon dialect, Wet season, Winter, Year, Year zero, 1 BC, 1,000,000, 1,000,000,000, 1000 (number), 2 BC, 365-day calendar. Expand index (158 more) » « Shrink index
An academic term (or simply "term") is a portion of an academic year, the time during which an educational institution holds classes.
An academic year or school year is a period of time which schools, colleges and universities use to measure a quantity of study.
The accusative case (abbreviated) of a noun is the grammatical case used to mark the direct object of a transitive verb.
In physical cosmology, the age of the universe is the time elapsed since the Big Bang.
The Ancient Greek language includes the forms of Greek used in ancient Greece and the ancient world from around the 9th century BC to the 6th century AD.
The terms anno Domini (AD) and before Christ (BC) are used to label or number years in the Julian and Gregorian calendars.
Anthropology is the study of humans and human behaviour and societies in the past and present.
In linguistics, apophony (also known as ablaut, (vowel) gradation, (vowel) mutation, alternation, internal modification, stem modification, stem alternation, replacive morphology, stem mutation, internal inflection etc.) is any sound change within a word that indicates grammatical information (often inflectional).
An apsis (ἁψίς; plural apsides, Greek: ἁψῖδες) is an extreme point in the orbit of an object.
Archaeology, or archeology, is the study of humanactivity through the recovery and analysis of material culture.
The Armenian calendar is the calendar traditionally used in Armenia and still used by the Armenian Apostolic Church and the Armenian Catholic Church.
The Astronomical AlmanacThe Astronomical Almanac for the Year 2015, (United States Naval Observatory/Nautical Almanac Office, 2014).
Astronomical year numbering is based on AD/CE year numbering, but follows normal decimal integer numbering more strictly.
Astronomy (from ἀστρονομία) is a natural science that studies celestial objects and phenomena.
Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania and numerous smaller islands.
Autumn, also known as fall in American and Canadian English, is one of the four temperate seasons.
Avestan, also known historically as Zend, is a language known only from its use as the language of Zoroastrian scripture (the Avesta), from which it derives its name.
In astronomy, axial precession is a gravity-induced, slow, and continuous change in the orientation of an astronomical body's rotational axis.
In astronomy, axial tilt, also known as obliquity, is the angle between an object's rotational axis and its orbital axis, or, equivalently, the angle between its equatorial plane and orbital plane.
The Aztec or Mexica calendar is the calendar system that was used by the Aztecs as well as other Pre-Columbian peoples of central Mexico.
Before Present (BP) years is a time scale used mainly in geology and other scientific disciplines to specify when events occurred in the past.
The Big Bang theory is the prevailing cosmological model for the universe from the earliest known periods through its subsequent large-scale evolution.
A billion years (109 years) is a unit of time on the petasecond scale, more precisely equal to seconds.
The Boston Latin School is a public exam school in Boston, Massachusetts.
The Brunhes–Matuyama reversal, named after Bernard Brunhes and Motonori Matuyama, was a geologic event, approximately 781,000 years ago, when the Earth's magnetic field last underwent reversal.
Cadmium is a chemical element with symbol Cd and atomic number 48.
A calendar is a system of organizing days for social, religious, commercial or administrative purposes.
A calendar era is the year numbering system used by a calendar.
Generally speaking, a calendar year begins on the New Year's Day of the given calendar system and ends on the day before the following New Year's Day, and thus consists of a whole number of days.
Canada is a country located in the northern part of North America.
In linguistics, more precisely in traditional grammar, a cardinal number or cardinal numeral (or just cardinal) is a part of speech used to count, such as the English words one, two, three, but also compounds, e.g. three hundred and forty-two (Commonwealth English) or three hundred forty-two (American English).
Celestial mechanics is the branch of astronomy that deals with the motions of celestial objects.
A century (from the Latin centum, meaning one hundred; abbreviated c.) is a period of 100 years.
Common Era or Current Era (CE) is one of the notation systems for the world's most widely used calendar era – an alternative to the Dionysian AD and BC system.
A common year is a calendar year with 365 days.
In statistics, dependence or association is any statistical relationship, whether causal or not, between two random variables or bivariate data.
Counting is the action of finding the number of elements of a finite set of objects.
The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic Period million years ago (mya) to the beginning of the Paleogene Period mya.
A day, a unit of time, is approximately the period of time during which the Earth completes one rotation with respect to the Sun (solar day).
Daylight, or the light of day, is the combination of all direct and indirect sunlight during the daytime.
A decade is a period of 10 years.
Dendrochronology (or tree-ring dating) is the scientific method of dating tree rings (also called growth rings) to the exact year they were formed in order to analyze atmospheric conditions during different periods in history.
Dinosaurs are a diverse group of reptiles of the clade Dinosauria.
The dry season is a yearly period of low rainfall, especially in the tropics.
Earth is the third planet from the Sun and the only astronomical object known to harbor life.
Earth's orbit is the trajectory along which Earth travels around the Sun.
The Eastern Orthodox Church, also known as the Orthodox Church, or officially as the Orthodox Catholic Church, is the second-largest Christian Church, with over 250 million members.
An eclipse is an astronomical event that occurs when an astronomical object is temporarily obscured, either by passing into the shadow of another body or by having another body pass between it and the viewer.
An eclipse season is one of only two periods during a year when eclipses can occur, due to the orbital inclination of the Moon.
The ecliptic is the circular path on the celestial sphere that the Sun follows over the course of a year; it is the basis of the ecliptic coordinate system.
The ecliptic coordinate system is a celestial coordinate system commonly used for representing the apparent positions and orbits of Solar System objects.
An educational institution is a place where people of different ages gain an education.
The Eemian (also called the last interglacial, Sangamonian, Ipswichian, Mikulin, Kaydaky, Valdivia or Riss-Würm) was the interglacial period which began about 130,000 years ago and ended about 115,000 years ago.
The ancient Egyptian calendar was a solar calendar with a 365-day year.
An ephemeris day is a period of 86,400 SI seconds.
The term ephemeris time (often abbreviated ET) can in principle refer to time in connection with any astronomical ephemeris.
In astronomy, an epoch is a moment in time used as a reference point for some time-varying astronomical quantity, such as the celestial coordinates or elliptical orbital elements of a celestial body, because these are subject to perturbations and vary with time.
In the fields of chronology and periodization, an epoch is an instant in time chosen as the origin of a particular era.
Eukaryotes are organisms whose cells have a nucleus enclosed within membranes, unlike Prokaryotes (Bacteria and other Archaea).
February 29, also known as leap day or leap year day, is a date added to most years that are divisible by 4, such as 2008, 2012, 2016, 2020, and 2024.
The federal government of the United States (U.S. federal government) is the national government of the United States, a constitutional republic in North America, composed of 50 states, one district, Washington, D.C. (the nation's capital), and several territories.
A fiscal year (or financial year, or sometimes budget year) is the period used by governments for accounting and budget purposes, which vary between countries.
Friedrich Wilhelm Bessel (22 July 1784 – 17 March 1846) was a German astronomer, mathematician, physicist and geodesist.
The full moon is the lunar phase when the Moon appears fully illuminated from Earth's perspective.
The Galactic Center is the rotational center of the Milky Way.
The galactic year, also known as a cosmic year, is the duration of time required for the Sun to orbit once around the center of the Milky Way Galaxy.
The Gaussian gravitational constant (symbol) is a parameter used in the orbital mechanics of the solar system.
A Gaussian year is defined as 365.2568983 days.
A geological period is one of several subdivisions of geologic time enabling cross-referencing of rocks and geologic events from place to place.
Geology (from the Ancient Greek γῆ, gē, i.e. "earth" and -λoγία, -logia, i.e. "study of, discourse") is an earth science concerned with the solid Earth, the rocks of which it is composed, and the processes by which they change over time.
German (Deutsch) is a West Germanic language that is mainly spoken in Central Europe.
Gothic is an extinct East Germanic language that was spoken by the Goths.
The term Great Year has a variety of related meanings.
The Gregorian calendar is the most widely used civil calendar in the world.
The Haab' is part of the Maya calendric system.
The Hebrew or Jewish calendar (Ha-Luah ha-Ivri) is a lunisolar calendar used today predominantly for Jewish religious observances.
The heliacal rising or star rise of a star, star cluster, or galaxy occurs annually when it becomes visible above the eastern horizon for a moment before sunrise, after a period of less than a year when it had not been visible.
Hindu calendar is a collective term for the various lunisolar calendars traditionally used in India.
The history of Earth concerns the development of planet Earth from its formation to the present day.
The Holocene is the current geological epoch.
Homo sapiens is the systematic name used in taxonomy (also known as binomial nomenclature) for the only extant human species.
An hour (symbol: h; also abbreviated hr.) is a unit of time conventionally reckoned as of a day and scientifically reckoned as 3,599–3,601 seconds, depending on conditions.
An ice age is a period of long-term reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers.
An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier.
India (IAST), also called the Republic of India (IAST), is a country in South Asia.
An integer (from the Latin ''integer'' meaning "whole")Integer 's first literal meaning in Latin is "untouched", from in ("not") plus tangere ("to touch").
Intercalation or embolism in timekeeping is the insertion of a leap day, week, or month into some calendar years to make the calendar follow the seasons or moon phases.
The International Astronomical Union (IAU; Union astronomique internationale, UAI) is an international association of professional astronomers, at the PhD level and beyond, active in professional research and education in astronomy.
The International System of Quantities (ISQ) is a system based on seven base quantities: length, mass, time, electric current, thermodynamic temperature, amount of substance, and luminous intensity.
The International Union of Geological Sciences (IUGS) is an international non-governmental organization devoted to international cooperation in the field of geology.
The International Union of Pure and Applied Chemistry (IUPAC) is an international federation of National Adhering Organizations that represents chemists in individual countries.
The Iranian calendars (گاهشماری ایرانی Gâhshomâriye Irâni) are a succession of calendars invented or used for over two millennia in Iran (Persia).
There are two official holidays in Islam: Eid Al-Fitr and Eid Al-Adha.
ISO 80000-3:2006 is an ISO standard entitled Quantities and units – Part 3: Space and time, superseding ISO 31-1 and ISO 31-2.
ISO 8601 Data elements and interchange formats – Information interchange – Representation of dates and times is an international standard covering the exchange of date- and time-related data.
The Jalali calendar is a solar calendar that was used in Iran (Persia), variants of which today are still in use in Iran as well as Afghanistan.
The Julian calendar, proposed by Julius Caesar in 46 BC (708 AUC), was a reform of the Roman calendar.
In astronomy, a Julian year (symbol: a) is a unit of measurement of time defined as exactly 365.25 days of SI seconds each.
The abbreviation kyr means "thousand years".
In the Earth's climate history the Last Glacial Maximum (LGM) was the last time period during the last glacial period when ice sheets were at their greatest extension.
Latin (Latin: lingua latīna) is a classical language belonging to the Italic branch of the Indo-European languages.
Latin declension is the set of patterns according to which Latin words are declined, or have their endings altered to show grammatical case and gender.
A leap year (also known as an intercalary year or bissextile year) is a calendar year containing one additional day (or, in the case of lunisolar calendars, a month) added to keep the calendar year synchronized with the astronomical or seasonal year.
The light-year is a unit of length used to express astronomical distances and measures about 9.5 trillion kilometres or 5.9 trillion miles.
This is a list of calendars.
This page indexes the individual years pages.
The long and short scales are two of several large-number naming systems for integer powers of ten that use the same words with different meanings.
A lunar calendar is a calendar based upon the monthly cycles of the Moon's phases (synodic months), in contrast to solar calendars, whose annual cycles are based only directly upon the solar year.
The lunar nodes are the orbital nodes of the Moon, that is, the two points at which the orbit of the Moon crosses the ecliptic.
Precession is the change in orientation of a rotational axis with respect to a reference plane.
The March equinox or Northward equinox is the equinox on the Earth when the subsolar point appears to leave the southern hemisphere and cross the celestial equator, heading northward as seen from Earth.
Mesoamerican calendars are the calendrical systems devised and used by the pre-Columbian cultures of Mesoamerica.
A metric prefix is a unit prefix that precedes a basic unit of measure to indicate a multiple or fraction of the unit.
A millennium (plural millennia or, rarely, millenniums) is a period equal to 1000 years, also called kiloyears.
The minute is a unit of time or angle.
A month is a unit of time, used with calendars, which is approximately as long as a natural period related to the motion of the Moon; month and Moon are cognates.
A Muslim (مُسلِم) is someone who follows or practices Islam, a monotheistic Abrahamic religion.
The abbreviation myr, "million years", is a unit of a quantity of (i.e.) years, or 31.6 teraseconds.
This article lists and discusses the usage and derivation of names of large numbers, together with their possible extensions.
The nativity of Jesus or birth of Jesus is described in the gospels of Luke and Matthew.
The Neolithic Revolution, Neolithic Demographic Transition, Agricultural Revolution, or First Agricultural Revolution, was the wide-scale transition of many human cultures during the Neolithic period from a lifestyle of hunting and gathering to one of agriculture and settlement, making an increasingly larger population possible.
New Scientist, first published on 22 November 1956, is a weekly, English-language magazine that covers all aspects of science and technology.
Nowruz (نوروز,; literally "new day") is the name of the Iranian New Year, also known as the Persian New Year, which is celebrated worldwide by various ethno-linguistic groups as the beginning of the New Year.
Old Church Slavonic, also known as Old Church Slavic (or Ancient/Old Slavonic often abbreviated to OCS; (autonym словѣ́ньскъ ѩꙁꙑ́къ, slověnĭskŭ językŭ), not to be confused with the Proto-Slavic, was the first Slavic literary language. The 9th-century Byzantine missionaries Saints Cyril and Methodius are credited with standardizing the language and using it in translating the Bible and other Ancient Greek ecclesiastical texts as part of the Christianization of the Slavs. It is thought to have been based primarily on the dialect of the 9th century Byzantine Slavs living in the Province of Thessalonica (now in Greece). It played an important role in the history of the Slavic languages and served as a basis and model for later Church Slavonic traditions, and some Eastern Orthodox and Eastern Catholic churches use this later Church Slavonic as a liturgical language to this day. As the oldest attested Slavic language, OCS provides important evidence for the features of Proto-Slavic, the reconstructed common ancestor of all Slavic languages.
Old English (Ænglisc, Anglisc, Englisc), or Anglo-Saxon, is the earliest historical form of the English language, spoken in England and southern and eastern Scotland in the early Middle Ages.
Old High German (OHG, Althochdeutsch, German abbr. Ahd.) is the earliest stage of the German language, conventionally covering the period from around 700 to 1050.
Old Norse was a North Germanic language that was spoken by inhabitants of Scandinavia and inhabitants of their overseas settlements from about the 9th to the 13th century.
In physics, an orbit is the gravitationally curved trajectory of an object, such as the trajectory of a planet around a star or a natural satellite around a planet.
The orbital period is the time a given astronomical object takes to complete one orbit around another object, and applies in astronomy usually to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars.
This list contains selected positive numbers in increasing order, including counts of things, dimensionless quantity and probabilities.
An order of magnitude of time is (usually) a decimal prefix or decimal order-of-magnitude quantity together with a base unit of time, like a microsecond or a million years.
The Oxford English Dictionary (OED) is the main historical dictionary of the English language, published by the Oxford University Press.
Oxford University Press (OUP) is the largest university press in the world, and the second oldest after Cambridge University Press.
Paleontology or palaeontology is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene Epoch (roughly 11,700 years before present).
In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction.
The pascal (symbol: Pa) is the SI derived unit of pressure used to quantify internal pressure, stress, Young's modulus and ultimate tensile strength.
The perihelion of any orbit of a celestial body about the Sun is the point where the body comes nearest to the Sun.
Physical cosmology is the study of the largest-scale structures and dynamics of the Universe and is concerned with fundamental questions about its origin, structure, evolution, and ultimate fate.
Physical Review is an American peer-reviewed scientific journal established in 1893 by Edward Nichols.
A planet is an astronomical body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.
The Pleistocene (often colloquially referred to as the Ice Age) is the geological epoch which lasted from about 2,588,000 to 11,700 years ago, spanning the world's most recent period of repeated glaciations.
The Pliocene (also Pleiocene) Epoch is the epoch in the geologic timescale that extends from 5.333 million to 2.58 million years BP.
Post-glacial rebound (also called isostatic rebound or crustal rebound) is the rise of land masses after the lifting of the huge weight of ice sheets during the last glacial period, which had caused isostatic depression.
Precession is a change in the orientation of the rotational axis of a rotating body.
Proto-Germanic (abbreviated PGmc; German: Urgermanisch; also called Common Germanic, German: Gemeingermanisch) is the reconstructed proto-language of the Germanic branch of the Indo-European languages.
Proto-Indo-European (PIE) is the linguistic reconstruction of the hypothetical common ancestor of the Indo-European languages, the most widely spoken language family in the world.
Pure and Applied Chemistry (abbreviated Pure Appl. Chem.) is the official journal for the International Union of Pure and Applied Chemistry (IUPAC).
Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon.
Ramadan (رمضان,;In Arabic phonology, it can be, depending on the region. also known as Ramazan, romanized as Ramzan, Ramadhan, or Ramathan) is the ninth month of the Islamic calendar, and is observed by Muslims worldwide as a month of fasting (Sawm) to commemorate the first revelation of the Quran to Muhammad according to Islamic belief.
In paleoanthropology, the recent African origin of modern humans, also called the "Out of Africa" theory (OOA), recent single-origin hypothesis (RSOH), replacement hypothesis, or recent African origin model (RAO), is the dominant model of the geographic origin and early migration of anatomically modern humans (Homo sapiens).
A red dwarf (or M dwarf) is a small and relatively cool star on the main sequence, of M spectral type.
The Revised Julian calendar, also known as the Milanković calendar, or, less formally, new calendar, is a calendar proposed by the Serbian scientist Milutin Milanković in 1923, which effectively discontinued the 340 years of divergence between the naming of dates sanctioned by those Eastern Orthodox churches adopting it and the Gregorian calendar that has come to predominate worldwide.
Sanskrit is the primary liturgical language of Hinduism; a philosophical language of Hinduism, Sikhism, Buddhism and Jainism; and a former literary language and lingua franca for the educated of ancient and medieval India.
A sea level rise is an increase in global mean sea level as a result of an increase in the volume of water in the world’s oceans.
A season is a division of the year marked by changes in weather, ecology, and amount of daylight.
The seasonal year is the time between successive recurrences of a seasonal event such as the flooding of a river, the migration of a species of bird, or the flowering of a species of plant.
The second is the SI base unit of time, commonly understood and historically defined as 1/86,400 of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each.
The International System of Units (SI) defines seven units of measure as a basic set from which all other SI units can be derived.
A sidereal year (from Latin sidus "asterism, star") is the time taken by the Earth to orbit the Sun once with respect to the fixed stars.
Sirius (a romanization of Greek Σείριος, Seirios,."glowing" or "scorching") is a star system and the brightest star in the Earth's night sky.
Soil fertility refers to the ability of a soil to sustain agricultural plant growth, i.e. to provide plant habitat and result in sustained and consistent yields of high quality.
A solar calendar is a calendar whose dates indicate the season or almost equivalently the position of the apparent position of the sun in relative to the stars.
The Solar Hijri calendar (gāh-shomāri-ye hejri-ye khorshidi; لمريز لېږدیز کلیز), also called the Solar Hejri calendar or Shamsi Hijri calendar, and abbreviated as SH, is the official calendar of Iran and Afghanistan.
The Solar SystemCapitalization of the name varies.
The Sothic cycle or Canicular period is a period of 1,461 Egyptian civil years of 365 days each or 1,460 Julian years averaging 365¼ days each.
Spring is one of the four conventional temperate seasons, following winter and preceding summer.
The subarctic climate (also called subpolar climate, subalpine climate, or boreal climate) is a climate characterised by long, usually very cold winters, and short, cool to mild summers.
The subtropics are geographic and climate zones located roughly between the tropics at latitude 23.5° (the Tropic of Cancer and Tropic of Capricorn) and temperate zones (normally referring to latitudes 35–66.5°) north and south of the Equator.
Summer is the hottest of the four temperate seasons, falling after spring and before autumn.
The Sun is the star at the center of the Solar System.
A supermoon is a full moon or a new moon that approximately coincides with the closest distance that the Moon reaches to Earth in its elliptic orbit, resulting in a slightly larger-than-usual apparent size of the lunar disk as seen from Earth.
Tantalum is a chemical element with symbol Ta and atomic number 73.
Tehran (تهران) is the capital of Iran and Tehran Province.
In geography, the temperate or tepid climates of Earth occur in the middle latitudes, which span between the tropics and the polar regions of Earth.
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.
Theropoda (or, from Greek θηρίον "wild beast" and πούς, ποδός "foot") or theropods are a dinosaur suborder characterized by hollow bones and three-toed limbs.
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).
Various schemes have been used or proposed for timekeeping on the planet Mars independently of Earth time and calendars.
A tropical year (also known as a solar year) is the time that the Sun takes to return to the same position in the cycle of seasons, as seen from Earth; for example, the time from vernal equinox to vernal equinox, or from summer solstice to summer solstice.
The tropics are a region of the Earth surrounding the Equator.
Tungsten, or wolfram, is a chemical element with symbol W (referring to wolfram) and atomic number 74.
Tyrannosaurus is a genus of coelurosaurian theropod dinosaur.
The Unified Code for Units of Measure (the UCUM) is a system of codes for unambiguously representing measurement units to both humans and machines.
A unit of time or time unit is any particular time interval, used as a standard way of measuring or expressing duration.
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain,Usage is mixed with some organisations, including the and preferring to use Britain as shorthand for Great Britain is a sovereign country in western Europe.
The United Kingdom Hydrographic Office (UKHO) is the UK's agency for providing hydrographic and marine geospatial data to mariners and maritime organisations across the world.
The United States of America (USA), commonly known as the United States (U.S.) or America, is a federal republic composed of 50 states, a federal district, five major self-governing territories, and various possessions.
The United States Government Publishing Office (GPO) (formerly the Government Printing Office) is an agency of the legislative branch of the United States federal government.
Universal Time (UT) is a time standard based on Earth's rotation.
The University of Massachusetts Press is a university press that is part of the University of Massachusetts Amherst.
Uranium–thorium dating, also called thorium-230 dating, uranium-series disequilibrium dating or uranium-series dating, is a radiometric dating technique established in the 1960s which has been used since the 1970s to determine the age of calcium carbonate materials such as speleothem or coral.
A varve is an annual layer of sediment or sedimentary rock.
Vedic Sanskrit is an Indo-European language, more specifically one branch of the Indo-Iranian group.
Vegetation is an assemblage of plant species and the ground cover they provide.
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days.
Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloudy.
A week is a time unit equal to seven days.
West Saxon was one of four distinct dialects of Old English.
The monsoon season, is the time of year when most of a region's average annual rainfall occurs.
Winter is the coldest season of the year in polar and temperate zones (winter does not occur in the tropical zone).
A year is the orbital period of the Earth moving in its orbit around the Sun.
Year zero does not exist in the Anno Domini system usually used to number years in the Gregorian calendar and in its predecessor, the Julian calendar.
Year 1 BC was a common year starting on Friday or Saturday (link will display the full calendar) of the Julian calendar (the sources differ, see leap year error for further information) and a leap year starting on Thursday of the Proleptic Julian calendar.
1,000,000 (one million), or one thousand thousand, is the natural number following 999,999 and preceding 1,000,001.
1,000,000,000 (one billion, short scale; one thousand million or milliard, yard, long scale) is the natural number following 999,999,999 and preceding 1,000,000,001.
1000 or one thousand is the natural number following 999 and preceding 1001.
Year 2 BC was a common year starting on Thursday or Friday (link will display the full calendar) of the Julian calendar (the sources differ, see leap year error for further information) and a common year starting on Wednesday of the Proleptic Julian calendar.
A 365-day calendar consists of exactly 365 days per year (no leap days), and is primarily used in computer models and as an assumption in every-day calculations.
525600, A (year), Annum, Annum (unit), Annus, Anomalistic year, Astronomical year, Draconic year, Draconitic year, Dracontic year, Earth year, Earth years, Eclipse year, Ecliptic year, Exa-annum, Exaannum, Exayear, Ga (unit), Giga-annum, Gigaanna, Gigaannum, Gigaannus, Gregorian Year, Gregorian year, Heliacal year, Kiloannum, Kiloannus, Ma (unit), Mega Year, Mega-annum, Megaannum, Megaannus, Megayear, Mya (unit), Petaanna, Petayear, SI annus, SI year, Terayear, The Year, The year, Twelvemonth, Tya (unit), Y and yr, Yaer, Year duration, Yearly, Years, Years ago, Yottayear, Zettayear.