出典:Wiktionary
出典:Wikipedia
出典:『Wikipedia』 (2011/06/13 18:18 UTC 版)
In Christianity, a moveable feast or movable feast is a holy day — a feast day or a fast day — whose date is not fixed to a particular day of the calendar year but moves in response to the date of Easter, the date of which varies according to a complex formula. Easter is itself a "moveable feast".