CHRISTIAN LITURGICAL YEAR. The Christian liturgical year consists of two cycles, differently defined in Eastern and Western traditions. The Eastern (Byzantine) rite distinguishes between movable and fixed festivals: the former are those whose dates vary each year with the date of Easter but always fall on the same days of the week; the dates of the latter are constant but may fall on any day of the week. Western tradition, on the other hand, includes with the movable festivals certain feasts whose date is fixed (most importantly, Christmas, December 25) and the seasons dependent on those. This whole cycle is known as the temporale, or (as in the present Roman Missal) the Proper of Seasons. The second cycle in Western tradition includes festivals of saints and other anniversaries on fixed dates and is called the sanctorale, the Proper of Saints.

Easter, the Christian Passover

The...