Advent, from the Latin “coming,” is a season of four weeks of preparation for the coming of Christ, which Christians commemorate on December 25. These four weeks are a time of joyful preparation for the Nativity of Jesus. During this time, readings from the prophets of the Old Testament focus on the promised coming of a Messiah while the Gospels focus on the eventual return of Christ to Earth. The Christian community in the Roman Catholic and Protestant parts of the Christian world celebrate the First Sunday of Advent four weeks before December 25. Orthodox Christians follow the Julian calendar and their Christmas celebration occurs slightly later.