Editing Year (section)

=== Summary ===
Some of the year lengths in this table are in average [[solar day]]s, which are slowly getting longer (at a rate that cannot be exactly predicted in advance) and are now around {{val|86400.002}} [[Second|SI seconds]].

{| class="wikitable sortable"
! scope="col" | Days
! scope="col" | Year type
|-
| 346.62             || Draconic, also called eclipse
|-
| 354.37             || Lunar
|-
| 365                || Solar days: vague, and a [[common year]] in many [[solar calendar]]s
|-
| {{val|365.24219}}  || Tropical, also called solar, averaged and then rounded for epoch [[J2000.0]]
|-
| {{val|365.2425}}   || Gregorian, solar days averaged over the 400-year cycle
|-
| {{val|365.25}}     || Julian, solar days averaged over the four-year cycle
|-
| {{val|365.25636}}  || Sidereal, for epoch [[J2000.0]]
|-
| {{val|365.259636}} || Anomalistic, averaged and then rounded for epoch J2011.0
|-
| 366                || [[Leap year]] in many [[solar calendar]]s
|}

An average Gregorian year may be said to be 365.2425 [[day]]s (52.1775 [[week]]s, and if an hour is defined as one twenty-fourth of a day, {{val|8765.82}} [[hour]]s, {{val|525949.2}} [[minute]]s or {{val|31556952}} [[second]]s). Note however that in absolute time the average Gregorian year is not adequately defined unless the period of the averaging (start and end dates) is stated, because each period of 400 years is longer (by more than 1000 seconds) than the preceding one as the rotation of the Earth slows. In this calendar, a common year is 365 days ({{val|8760}} hours, {{val|525600}} minutes or {{val|31536000}} seconds), and a leap year is 366 days ({{val|8784}} hours, {{val|527040}} minutes or {{val|31622400}} seconds). The 400-year civil cycle of the Gregorian calendar has {{val|146097}} days and hence exactly {{val|20871}} weeks.