
Russian Patriarch Kirill celebrates a Christmas service in Christ the Savior Cathedral in Moscow on Jan. 7, 2015. Orthodox Christians celebrate Christmas on Jan. 7 in the Middle East, Russia, and other Orthodox churches that use the old Julian calendar instead of the 17th-century Gregorian calendar adopted by Catholics, Protestants, Greek Orthodox, and commonly used in secular life around the world. Kirill Kudryavtsev/AFP/Getty Images