Christmas is the Christian celebration of the birth of Jesus, observed on December 25 by most churches and on January 7 by Orthodox churches that follow the Julian calendar. Western churches prepare for it during Advent, and Orthodox Christians keep the Nativity Fast. By tradition, the Twelve Days of Christmas run from December 25 to Epiphany on January 6, and common practices include church services, nativity scenes, carols, decorated trees, and gift-giving.