The liturgical year, also called the church year, Christian year or kalendar, consists of the cycle of liturgical days and seasons that determines when feast days, including celebrations of saints, are to be observed, and which portions of scripture are to be read.

Christian liturgy is a pattern for worship used by a Christian congregation or denomination on a regular basis. The term liturgy comes from Greek and means "public work". Within Christianity, liturgies descending from the same region, denomination, or culture are described as ritual families.