Year

An analemma illustrates the changing position of the Sun over the course of a year, as viewed from a fixed time of day.

A year is the orbital period of the Earth moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by change in weather, the hours of daylight, and, consequently, vegetation and soil fertility. The current year is 2018.

In temperate and subpolar regions around the planet, four seasons are generally recognized: spring, summer, autumn, and winter. In tropical and subtropical regions, several geographical sectors do not present defined seasons; but in the seasonal tropics, the annual wet and dry seasons are recognized and tracked.

A calendar year is an approximation of the number of days of the Earth's orbital period as counted in a given calendar. The Gregorian calendar, or modern calendar, presents its calendar year to be either a common year of 365 days or a leap year of 366 days, as do the Julian calendars; see below. For the Gregorian calendar, the average length of the calendar year (the mean year) across the complete leap cycle of 400 years is 365.2425 days. The ISO standard ISO 80000-3, Annex C, supports the symbol a (for Latin annus) to represent a year of either 365 or 366 days. In English, the abbreviations y and yr are commonly used.

In astronomy, the Julian year is a unit of time; it is defined as 365.25 days of exactly 86,400 seconds (SI base unit), totalling exactly 31,557,600 seconds in the Julian astronomical year.[1]

The word year is also used for periods loosely associated with, but not identical to, the calendar or astronomical year, such as the seasonal year, the fiscal year, the academic year, etc. Similarly, year can mean the orbital period of any planet; for example, a Martian year or a Venusian year are examples of the time a planet takes to transit one complete orbit. The term can also be used in reference to any long period or cycle, such as the Great Year.[2]

Etymology

English year (via West Saxon ġēar (/jɛar/), Anglian ġēr) continues Proto-Germanic *jǣran (*jē₁ran). Cognates are German Jahr, Old High German jār, Old Norse ár and Gothic jer, from the Proto-Indo-European noun *yeh₁r-om "year, season". Cognates also descended from the same Proto-Indo-European noun (with variation in suffix ablaut) are Avestan yārǝ "year", Greek ὥρα (hṓra) "year, season, period of time" (whence "hour"), Old Church Slavonic jarŭ, and Latin hornus "of this year".

Latin annus (a 2nd declension masculine noun; annum is the accusative singular; annī is genitive singular and nominative plural; annō the dative and ablative singular) is from a PIE noun *h₂et-no-, which also yielded Gothic aþn "year" (only the dative plural aþnam is attested).

Although most languages treat the word as thematic *yeh₁r-o-, there is evidence for an original derivation with an *-r/n suffix, *yeh₁-ro-. Both Indo-European words for year, *yeh₁-ro- and *h₂et-no-, would then be derived from verbal roots meaning "to go, move", , *h₁ey- and *h₂et-, respectively (compare Vedic Sanskrit éti "goes", atasi "thou goest, wanderest"). A number of English words are derived from Latin annus, such as annual, annuity, anniversary, etc.; per annum means "each year", anno Domini means "in the year of the Lord".

The Greek word for "year", ἔτος, is cognate with Latin vetus "old", from the PIE word *wetos- "year", also preserved in this meaning in Sanskrit vat-sa-ras "year" and vat-sa- "yearling (calf)", the latter also reflected in Latin vitulus "bull calf", English wether "ram" (Old English weðer, Gothic wiþrus "lamb").

In some languages, it is common to count years by referencing to one season, as in "summers", or "winters", or "harvests". Examples include Chinese "year", originally , an ideographic compound of a person carrying a bundle of wheat denoting "harvest". Slavic besides godŭ "time period; year" uses lěto "summer; year".

In the International System of Quantities (ISO 80000-3), the year (symbol, a) is defined as either 365 days or 366 days.

Other Languages
Afrikaans: Jaar
Alemannisch: Jahr
አማርኛ: አመት
Ænglisc: Gēar
Аҧсшәа: Ашықәс
العربية: سنة
aragonés: Anyo
armãneashti: Anu
অসমীয়া: বছৰ
asturianu: Añu
Avañe'ẽ: Ro'y
Aymar aru: Mara
azərbaycanca: İl
تۆرکجه: ایل
বাংলা: বছর
Bân-lâm-gú:
Basa Banyumasan: Taun
башҡортса: Йыл
беларуская: Год
беларуская (тарашкевіца)‎: Год
भोजपुरी: साल
български: Година
Boarisch: Joar
བོད་ཡིག: ལོ་
bosanski: Godina
brezhoneg: Bloaz
буряад: Жэл
català: Any
Чӑвашла: Çулталăк
Cebuano: Tuig
čeština: Rok
Chamoru: Såkkan
chiShona: Gore
Cymraeg: Blwyddyn
dansk: År
davvisámegiella: Jahki
Deutsch: Jahr
dolnoserbski: Lěto
eesti: Aasta
Ελληνικά: Έτος
emiliàn e rumagnòl: An
эрзянь: Ие
español: Año
Esperanto: Jaro
euskara: Urte
فارسی: سال
Fiji Hindi: Saal
føroyskt: Ár
Frysk: Jier
furlan: An
Gaeilge: Bliain
Gaelg: Blein
Gàidhlig: Bliadhna
贛語:
ગુજરાતી: વર્ષ
𐌲𐌿𐍄𐌹𐍃𐌺: 𐌾𐌴𐍂
客家語/Hak-kâ-ngî: Ngièn
한국어:
Hawaiʻi: Makahiki
Հայերեն: Տարի
हिन्दी: वर्ष
hornjoserbsce: Lěto
hrvatski: Godina
Ido: Yaro
Ilokano: Tawen
Bahasa Indonesia: Tahun
interlingua: Anno
ᐃᓄᒃᑎᑐᑦ/inuktitut: ᐅᑭᐅᖅ
Iñupiak: Ukiuq
Ирон: Аз
íslenska: Ár
italiano: Anno
עברית: שנה
Basa Jawa: Taun
ಕನ್ನಡ: ವರ್ಷ
къарачай-малкъар: Джыл
ქართული: წელი
kaszëbsczi: Rok
қазақша: Жыл
kernowek: Bledhen
Kinyarwanda: Umwaka
Kiswahili: Mwaka
Kreyòl ayisyen: Lane
kurdî: Sal
Кыргызча: Жыл
кырык мары: И
Ladino: Anyo
лезги: Йис
ລາວ: ປີ
Latina: Annus
latviešu: Gads
Lëtzebuergesch: Joer
lietuvių: Metai
Limburgs: Jaor
Livvinkarjala: Vuozi
la .lojban.: nanca
lumbaart: Ann
magyar: Év
मैथिली: साल
македонски: Година
മലയാളം: വർഷം
Māori: Tau
मराठी: वर्ष
مصرى: سنه
Bahasa Melayu: Tahun
Baso Minangkabau: Tahun
Mìng-dĕ̤ng-ngṳ̄: Nièng
монгол: Жил
မြန်မာဘာသာ: သက္ကရာဇ်
Nederlands: Jaar
नेपाली: वर्ष
नेपाल भाषा: दँ
日本語:
Napulitano: Anno
нохчийн: Шо
Nordfriisk: Juar
norsk: År
norsk nynorsk: År
Nouormand: Aun
occitan: Annada
олык марий: Идалык
oʻzbekcha/ўзбекча: Yil
پنجابی: ورہ
پښتو: کال
Patois: Ier
Tok Pisin: Yia
Plattdüütsch: Johr
polski: Rok
português: Ano
română: An
Romani: Bersh
Runa Simi: Wata
русиньскый: Рік
русский: Год
саха тыла: Сыл
संस्कृतम्: वर्षः
sardu: Annu
Scots: Year
Sesotho sa Leboa: Ngwaga
shqip: Viti
sicilianu: Annu
සිංහල: වර්ෂය
Simple English: Year
سنڌي: سال
slovenčina: Rok
slovenščina: Leto
ślůnski: Rok (czas)
Soomaaliga: Sanad
کوردی: ساڵ
Sranantongo: Yari
српски / srpski: Година
srpskohrvatski / српскохрватски: Godina
Basa Sunda: Taun
suomi: Vuosi
svenska: År
Tagalog: Taon
தமிழ்: ஆண்டு
татарча/tatarça: Ел
తెలుగు: సంవత్సరము
ไทย: ปี
тоҷикӣ: Солҳо
Türkçe: Yıl
українська: Рік
اردو: سال
Vahcuengh: Bi
vèneto: An
Tiếng Việt: Năm
Võro: Aastak
walon: Anêye
West-Vlams: Joar
Winaray: Tuig
Wolof: At
吴语:
ייִדיש: יאר
Yorùbá: Ọdún
粵語:
Zeêuws: Jaer
žemaitėška: Metā
中文:
डोटेली: वर्ष
ГӀалгӀай: Шу
Kabɩyɛ: Pɩnaɣ