### Noun

1 a late time of life; "old age is not for
sissies"; "he's showing his years"; "age hasn't slowed him down at
all"; "a beard white with eld"; "on the brink of geezerhood" [syn:
old age,
age, eld, geezerhood]

2 a prolonged period of time; "we've known each
other for ages"; "I haven't been there for years and years" [syn:
long
time, age]

3 the time during which someone's life continues;
"the monarch's last days"; "in his final years" [syn: days]

# English

## Pronunciation

- a UK /ji.ə(ɹ)z/|/jɜː(ɹ)z/, /ji.@(r)z/|/j3:(r)z/

## Noun

years- Plural of year
- "It will be a shorter book and it will not start four million years ago," he said with a smile at an awards ceremony in the Pennsylvania state Capitol. - Earliest Usenet use via Google Groups: fa.sf-lovers, 05 May 1981 1718-PDT, Jim McGrath

- An unusually long time
- It took years for the bus to come.

### Synonyms

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. By
extension, this can be applied to any planet: for example, a "Martian
year" is the time in which Mars completes its own orbit.

# Etymology

West Saxon gear, Anglian gēr continues Proto-Germanic *jǣram (*jē2ram). Cognates are Old High German jar, Old Norse ár and Gothic jer, all from a PIE *yērom "year, season". Cognates outside of Germanic are Avestan yare "year", Greek "year, season, period of time" (whence "hour"), Old Church Slavonic jaru and Latin hornus "of this year".Latin annum is from a base *at-no-. Both *yē-ro-
and *at-no- are based on verbal roots expressing movement, *at- and
*ey- respectively, both meaning "to go" generally. Latin annum has
a cognate in Gothic aþnam "year". The Greek word for "year", , is
cognate to Latin vetus "old", from PIE *wetus- "year" , also
preserved in this meaning in Sanskrit "yearling
(calf)".

The Gregorian
calendar attempts to keep the vernal
equinox on or close to March 21; hence
it follows the vernal equinox
year. The average length of this calendar's year is 365.2425
days (which can be thought of as 97 out of 400 years being leap
years) whereas the vernal equinox year is 365.2424 days.

Among solar calendars in wide use today, the
Persian
calendar is one of the most precise. Rather than being based on
numerical rules, the Persian year begins on the day (for the time
zone of Tehran) on which the
vernal equinox actually falls, as determined by precise
astronomical computations.

No astronomical year has an integer number of
days or lunar months, so any calendar that follows an astronomical
year must have a system of intercalation such as
leap
years.

In the Julian
calendar, the average length of a year was 365.25 days. (This
is still used as a convenient time unit in astronomy as shown
below.) In a non-leap year, there are 365 days, in a leap year
there are 366 days. A leap year occurs every 4 years.

# Seasonal year

A 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, the flowering of a species of plant, the first frost, or the first scheduled game of a certain sport. All of these events can have wide variations of more than a month from year to year.# Fiscal year

A fiscal year is a 12-month period used for calculating annual financial statements in businesses and other organizations. In many jurisdictions, regulations regarding accounting require such reports once per twelve months, but do not require that the twelve months constitute a calendar year. For example, the federal government of the U.S. has a fiscal year that starts on October 1st instead of January 1st. In Australia the financial year runs from July 1st. In Canada, from April 1st.# Academic year

An academic year refers to the annual period during which a student attends school, college or university.The school year can be divided up in various
ways, two of which are most common in North American educational
systems.

- Many schools divide the academic year into three roughly equal-length trimesters (called terms in the UK), more or less coinciding with autumn, winter, and spring. At some, a somewhat shortened summer session, not usually considered part of the regular academic year, is attended by students on a voluntary or elective basis.
- Other schools break the year into two main semesters, a first (typically August through December) and a second (January through May). Each of these main semesters may be split in half by mid-term exams, and each of the halves is referred to as a quarter (or term in some countries). There may also be an elective summer session, and/or a short January session.
- Some other places, such in the United States, have four 'marking periods.' The school year startes in early September and ends in Mid-June. There are 180 days in all of school(excluding weekends and breaks.) Most commonly, there is a summer break, last two weeks of June to the beginning of September.

# Astronomical years

## Julian year

The Julian year, as used in astronomy and other sciences, is a time unit defined as exactly 365.25 days. This is the normal meaning of the unit "year" (symbol "a" from the Latin annus, annata) used in various scientific contexts. The Julian century of 36,525 days and the Julian millennium of 365,250 days are used in astronomical calculations. Fundamentally, expressing a time interval in Julian years is a way to precisely specify how many days (not how many "real" years), for long time intervals where stating the number of days would be unwieldy and unintuitive. By convention, the Julian year is used in the computation of the distance covered by a light-year.## Sidereal, tropical, and anomalistic years

- The relations among these are considered more fully in Precession (astronomy).

Each of these three years can be loosely called
an 'astronomical year'.

The sidereal
year is the time taken for the Earth to complete one revolution
of its orbit, as measured against a fixed frame of reference (such
as the fixed stars, Latin sidera, singular sidus). Its duration in
SI days of
86,400 SI seconds each is on average:

The tropical
year is the time taken for the Earth to complete one revolution
with respect to the framework provided by the intersection of the
ecliptic (the plane of
the orbit of the Earth) and the plane of the equator (the plane perpendicular
to the rotation axis of the Earth). The exact length of a tropical
year slightly depends on the chosen starting point: for example the
vernal equinox year is the time between successive vernal
equinoxes. The mean tropical year (averaged over all ecliptic
points) is:

- 365.242 189 67 days (365 d 5 h 48 min 45 s) (at the epoch J2000.0).

The anomalistic year is the time taken for the
Earth to complete one revolution with respect to its apsides. The orbit of
the Earth is elliptical; the extreme points, called apsides, are
the perihelion, where
the Earth is closest to the Sun (January 3 in
2008), and the
aphelion, where the
Earth is farthest from the Sun (July 4 in 2008).
The anomalistic year is usually defined as the time between two
successive perihelion passages. Its average duration is:

- 365.259 635 864 days (365 d 6 h 13 min 52 s) (at the epoch J2000.0).

## Draconic year

The draconic year, draconitic year, eclipse year, or ecliptic year is the time taken for the Sun (as seen from the Earth) to complete one revolution with respect to the same lunar node (a point where the Moon's orbit intersects the ecliptic). This period is associated with eclipses: these occur only when both the Sun and the Moon are near these nodes; so eclipses occur within about a month of every half eclipse year. Hence there are two eclipse seasons every eclipse year. The average duration of the eclipse year is:- 346.620 075 883 days (346 d 14 h 52 min 54 s) (at the epoch J2000.0).

## Full moon cycle

The full moon cycle is the time for the Sun (as seen from the Earth) to complete one revolution with respect to the perigee of the Moon's orbit. This period is associated with the apparent size of the full moon, and also with the varying duration of the synodic month. The duration of one full moon cycle is:- 411.784 430 29 days (411 d 18 h 49 min 34 s) (at the epoch J2000.0).

## Lunar year

The lunar year comprises twelve full cycles of the phases of the Moon, as seen from Earth. It has a duration of approximately 354.37 days.## Heliacal year

A heliacal year is the interval between the heliacal risings of a star. It differs from the sidereal year for stars away from the ecliptic due mainly to the precession of the equinoxes (To visualise: the constellation Crux which rose and set as seen from the Mediterranean in ancient Greek times, is never above the horizon in current times.)## Sothic year

The Sothic year is the interval between heliacal risings of the star Sirius. Its duration is very close to the mean Julian year of 365.25 days.## Gaussian year

The Gaussian year is the sidereal year for a planet of negligible mass (relative to the Sun) and unperturbed by other planets that is governed by the Gaussian gravitational constant. Such a planet would be slightly closer to the Sun than Earth's mean distance. Its length is:- 365.256 898 3 days (365 d 6 h 9 min 56 s).

## Besselian year

The Besselian year is a tropical year that starts when the fictitious mean Sun reaches an ecliptic longitude of 280°. This is currently on or close to 1 January. It is named after the 19th century German astronomer and mathematician Friedrich Bessel. An approximate formula to compute the current time in Besselian years from the Julian day is:- B = 2,000 + (JD - 2,451,544.53) /365.242189

## Great year

The Great year, Platonic year, or Equinoctial cycle corresponds to a complete revolution of the equinoxes around the ecliptic. Its length is about 25,700 years, and cannot be determined precisely as the precession speed is variable.## Galactic year

The Galactic year is the time it takes Earth's solar system to revolve once around the galactic center. It comprises roughly 226 million Earth years.# Variation in the length of the year and the day

The exact length of an astronomical year changes over time. The main sources of this change are:- The precession of the equinoxes changes the position of astronomical events with respect to the apsides of Earth's orbit. An event moving toward perihelion recurs with a decreasing period from year to year; an event moving toward aphelion recurs with an increasing period from year to year. But this effect don't change the average value of the length of the year.

- The gravitational influence of the Moon and planets changes the motion of the Earth from a steady orbit around the Sun. The Earth orbit varies by a chaotic way, but in a interval quite more reduced than the orbits of the nearest planets.

- Tidal drag between the Earth and the Moon and Sun increases the length of the day and of the month (by transferring angular momentum from the rotation of the Earth to the revolution of the Moon); since the apparent mean solar day is the unit with which we measure the length of the year in civil life, the length of the year appears to change. Tidal drag in turn depends on factors such as post-glacial rebound and sea level rise.

- Changes in the effective mass of the Sun, caused by solar wind and radiation of energy generated by nuclear fusion and radiated by its surface, will affect the Earth's orbital period over a long time (approximately an extra 1.25 microsecond per year).

- Other effects tend to shorten the Earth's orbital period: the Poynting-Robertson effect (about 30 nanoseconds per year). And the gravitational radiation (by about 165 attoseconds per year) . . .

# Summary of various kinds of year

- 346.62 days - a draconitic year in some septenary calendars.
- 353, 354 or 355 days — the lengths of common years in some lunisolar calendars.
- 354.37 days/12 lunar months - the average length of a year in lunar calendars.
- 365 days — a common year in many solar calendars.
- 365.24219 days — a mean tropical year near the year 2000.
- 365.2424 days — a vernal equinox year.
- 365.2425 days — the average length of a year in the Gregorian calendar.
- 365.25 days — the average length of a year in the Julian calendar.
- 365.2564 days — a sidereal year.
- 366 days — a leap year in many solar calendars.
- 383, 384 or 385 days — the lengths of leap years in some lunisolar calendars.
- 383.9 days/13 lunar months - a leap year in some lunisolar calendars.

An average Gregorian year is 365.2425 days = 52.1775 weeks, 8,765.82 hours = 525,949.2 minutes = 31,556,952 seconds (mean solar, not SI). A
common year is 365 days = 8,760 hours = 525,600 minutes =
31,536,000 seconds. A leap year is 366 days = 8,784 hours = 527,040
minutes = 31,622,400 seconds. The 400-year cycle of the Gregorian
calendar has 146,097 days and hence exactly 20,871 weeks. See also
numerical facts about the Gregorian calendar.

# Numeration or designation of year numbers

A calendar era is used to assign a number to individual years, using a reference point in the past as the beginning of the era. In many countries, the most common era is from the estimated date of the birth of Jesus Christ; dates in this era are designated anno Domini ("in the year of the Lord", abbreviated A.D.) or, more neutrally, C.E. (common era). Other eras are also used to enumerate the years in different cultural, religious or scientific contexts.# Notes and References

# See also

- List of calendars
- Jera
- annum - 100 years - base unit
- Man-year

years in Afrikaans: Jaar

years in Tosk Albanian: Jahr

years in Arabic: عام

years in Aragonese: Año

years in Official Aramaic (700-300 BCE): ܫܢܬܐ
(ܙܒܢܐ)

years in Asturian: Añu

years in Aymara: Mara

years in Min Nan: Nî

years in Belarusian: Год

years in Belarusian (Tarashkevitsa): Год

years in Bosnian: Godina

years in Breton: Bloaz

years in Bulgarian: Година

years in Catalan: Any

years in Chuvash: Çул

years in Cebuano: Tuig

years in Czech: Rok

years in Welsh: Blwyddyn

years in Danish: År

years in German: Jahr

years in Estonian: Aasta

years in Modern Greek (1453-): Έτος

years in Emiliano-Romagnolo: Ân

years in Erzya: Ие

years in Spanish: Año

years in Esperanto: Jaro

years in Basque: Urte

years in Persian: سال

years in French: Année (calendrier)

years in Western Frisian: Jier

years in Friulian: An

years in Irish: Bliain

years in Gan Chinese: 年

years in Scottish Gaelic: Bliadhna

years in Galician: Ano

years in Korean: 년

years in Croatian: Godina

years in Ido: Yaro

years in Indonesian: Tahun

years in Interlingua (International Auxiliary
Language Association): Anno

years in Inuktitut: ᐅᑭᐅᖅ/ukuiq

years in Ossetian: Аз

years in Icelandic: Ár

years in Italian: Anno

years in Hebrew: שנה

years in Javanese: Taun

years in Georgian: წელი

years in Swahili (macrolanguage): Mwaka

years in Haitian: Lane

years in Kurdish: Sal

years in Ladino: Anyo

years in Lao: ປີ

years in Latin: Annus

years in Latvian: Gads

years in Luxembourgish: Joer

years in Lithuanian: Metai

years in Limburgan: Jaor

years in Hungarian: Év

years in Maori: Tau

years in Malay (macrolanguage): Tahun

years in Mongolian: Жил

years in Dutch: Jaar

years in Japanese: 年

years in Norwegian: År

years in Norwegian Nynorsk: År

years in Narom: Aun

years in Occitan (post 1500): Annada

years in Uzbek: Yil

years in Low German: Johr

years in Polish: Rok

years in Portuguese: Ano

years in Romanian: An

years in Vlax Romani: Bersh

years in Quechua: Wata

years in Russian: Год

years in Albanian: Viti

years in Sicilian: Annu

years in Simple English: Year

years in Slovak: Rok

years in Slovenian: Leto

years in Somali: Sanad

years in Serbian: Година

years in Serbo-Croatian: Godina

years in Sundanese: Taun

years in Finnish: Vuosi

years in Swedish: År

years in Tagalog: Taon

years in Tamil: ஆண்டு

years in Telugu: సంవత్సరము

years in Thai: ปี

years in Tok Pisin: Yia

years in Turkish: Yıl

years in Ukrainian: Рік

years in Urdu: سال

years in Võro: Aastak

years in Yiddish: יאר

years in Yoruba: Ọdún

years in Contenese: 年

years in Samogitian: Metā

years in Chinese: 年