Changes

A '''year''' is about 365 [[day]]s (except in a [[leap year]]). It is the time it takes the [[Earth]] to go completely around ([[orbit]]) the [[sun]] once. A year is actually almost 365.25 days long, but a [[calendar]] has 365 days, except in a [[leap year]], which has 366 days.<ref>{{Cite web|title=What Is a Leap Year? {{!}} NASA Space Place – NASA Science for Kids|url=https://spaceplace.nasa.gov/leap-year/en/|access-date=2023-05-17|website=spaceplace.nasa.gov}}</ref>

A '''year (yr)''' is about 365 [[day]]s (except in a [[leap year]]). It is the time it takes the [[Earth]] to go completely around ([[orbit]]) the [[sun]] once. A year is actually almost 365.25 days long, but the [[Gregorian calendar|Gregorian]] and [[Julian calendar|Julian]] [[calendar]] has 365 days, except in a [[leap year]], which has 366 days.<ref>{{Cite web|title=What Is a Leap Year? {{!}} NASA Space Place – NASA Science for Kids|url=https://spaceplace.nasa.gov/leap-year/en/|access-date=2023-05-17|website=spaceplace.nasa.gov}}</ref>

The year starts on [[January 1]] and ends on [[December 31]] in the [[Gregorian calendar]], but a [[fiscal year]] or a [[school year]] can start on a different day of the year.

The year starts on [[January 1]] and ends on [[December 31]] in the [[Gregorian calendar|Gregorian]] and [[Julian calendar]] but a [[fiscal year]] or a [[school year]] can start or end on a different day.

There are several ways used to measure the length of a year.

There are several ways used to measure the length of a year.

* a '''solar''' year, also called '''tropical year''', is based on the [[season]]s.  The [[Gregorian calendar]] is based on a tropical year of 365.2425 days.  This 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 word "tropical" in this sense comes from the Greek ''tropikos'' meaning "turn".

* a '''solar''' year, also called '''tropical year''', is based on the [[season]]s.  The [[Gregorian calendar]] is based on a tropical year of 365.2425 days.  This 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 word "tropical" in this sense comes from the Greek ''tropikos'' meaning "turn".

* a '''lunar''' year is based on the [[moon]] and is usually 12 [[Month|lunar months]] (29 days, 12 [[hour]]s, 44 [[minute]]s each) or 354 days long.

* a '''lunar''' year is based on the [[moon]] and is  

* usually 12 [[Month|lunar months]] (29 days, 12 [[hour]]s, 44 [[minute]]s each) or 354/355 days long.

* a '''sidereal''' year measures the time between when a selected [[star|fixed star]] is highest in the [[night|night]] [[sky]].

* a '''sidereal''' year measures the time between when a selected [[star|fixed star]] is highest in the [[night|night]] [[sky]].

* an '''anomalistic year''' is the difference between the times when the Earth gets closest to the sun.

* an '''anomalistic year''' is the difference between the times when the Earth gets closest to the sun.