From Wikipedia, the free encyclopedia
Jump to: navigation, search

Lunation is the mean (average) time for one lunar phase cycle (i.e., the synodic period of the Moon, or the amount of time from one new moon to the next).

In the year 2000, the average length of a lunation was 29.530588 days (or 29 days, 12 hours, 44 minutes, and 3 seconds). However, the length of any one synodic month can vary from 29.26 to 29.80 days due to the perturbing effects of the Sun's gravity on the Moon's eccentric orbit.[1]

The length of a lunation is linked to many phenomena in nature, such as the variation between spring and neap tides (the extreme highest and lowest tides, respectively).

In a lunar calendar, each month corresponds to a lunation. Each lunar cycle can be assigned a unique Lunation Number to identify it.

See also[edit]


  1. ^ Espenak, Fred. "Six Millennium Catalog of Phases of the Moon". NASA Eclipse Web Site. NASA. Retrieved 13 August 2013.