Noun
a religious holiday that falls on different dates in different years
Source: WordNetIf you are lucky enough to have lived in Paris as a young man, then wherever you go for the rest of your life it stays with you, for Paris is a moveable feast. Ernest Hemingway
A living museum must surely see itself as a locus of argument. A breathing art institution is not a lockup but a moveable feast. Andrew O'Hagan
For example, the start of Advent is the Sunday nearest November 30. In addition, the observance of some fixed feasts may move a few days in a particular year to not clash with that year's date for a more important moveable feast. Source: Internet
That mos gallicanus (French custom) bound to a moveable feast was introduced in France by king Philip Augustus (1165–1180–1223), maybe to establish a new style in the provinces reconquered from England. Source: Internet