Editing Full moon (section)

===Formula===
The date and approximate time of a specific full moon (assuming a circular orbit) can be calculated from the following equation:<ref>{{Cite book| first = Jean | last = Meeus | date= 1998 | title = Astronomical Algorithms | edition = 2nd |isbn = 0-943396-61-1| chapter = Phases of the Moon | pages = 349–354 | publisher = Willmann-Bell | location = Richmond, Virginia}}</ref>
:<math> d = 20.362000+ 29.530588861 \times N + 102.026 \times 10^{-12} \times N^2</math>
where ''d'' is the number of days since 1 January 2000 00:00:00 in the [[Terrestrial Time]] scale used in astronomical [[Ephemeris|ephemerides]]; for [[Universal Time]] (UT) add the following approximate correction to ''d'':
: <math>-0.000739 - (235 \times 10^{-12})\times N^2</math> days
where ''N'' is the number of full moons since the first full moon of 2000. The true time of a full moon may differ from this approximation by up to about 14.5 hours as a result of the non-circularity of the Moon's orbit.<ref>{{Cite book| last = Meeus | first = Jean | chapter = The Duration of the Lunation |title= More Mathematical Astronomy Morsels | publisher = Willmann-Bell |location=Richmond, Virginia| date = 2002 | pages = 19–31 | isbn = 0-943396-74-3}}</ref> See [[New moon]] for an explanation of the formula and its parameters.

The age and apparent size of the full moon vary in a cycle of just under 14 [[synodic month]]s, which has been referred to as a [[full moon cycle]].