Moveable feast

In Christianity, a moveable feast or movable feast is a holy day -- a feast or a fast -- whose date is not fixed to a particular day of the calendar year but moves in response to the date of Easter, which date varies according to a complex formula.

By extension, other religions' feasts are occasionally described by the same term. In addition many countries have secular holidays that are moveable, for instance to make holidays more consecutive; the term "moveable feast" is not used in this case however.

Further, by metaphoric extension but with the meaning of a party that was on the move, Ernest Hemingway used the term as the title for his memoirs, A Moveable Feast, of life in Paris in the 1920s. This usage has become a popular phrase in food contexts.

Moveable feasts in Christianity

Mardi Gras and Ash Wednesday - 40 days before Easter
Easter - the date around which the others are placed
Ascension Day - 40 days after Easter
Pentecost - 50 days after Easter
Corpus Christi - 60 days after Easter
feast days of some significant saints days, if a movable feast falls too close to their usual date.

Fixed feasts in Christianity

Christmas - December 25
Transfiguration - August 6
Dormition of the Theotokos - August 15
Presentation of Christ in the Temple - February 2
Exaltation of the Cross - September 15
feast days of most individual saints

Moveable feasts in Japanese calendar

Coming-of-age Day (成人の日) - 2nd Monday of January
Maritime Day (海の日) - 3rd Monday of July
Respect-for-the-aged Day (敬老の日) - 3rd Monday of September
Health-Sports Day (体育の日) - 2nd Monday of October

Moveable US public holidays