出典:Wikipedia
出典:『Wikipedia』 (2011/06/07 09:58 UTC 版)
In astronomy and calendar studies, the Callippic cycle (or Calippic) is a particular approximate common multiple of the year (specifically the tropical year) and the synodic month, that was proposed by Callippus in 330 BC. It is a period of 76 years, as an improvement on the 19-year Metonic cycle.