Why is Christmas always on December 25, but Easter is on different Sundays? What are the origins of Advent? The Church keeps time based on the life of Christ, with its most important seasons corresponding to the major events in the life of Jesus. The liturgical year is also strongly linked to the Church's early rites of initiation. This handbook guides you through the history and nuances of the Church year. Especially helpful in planning school liturgies and prayer services.