A Different Day Each Year

Easter falls on a different day each year. But have you ever stopped and wondered why? Back in 1582, Pope Gregory XIII decreed the use of the Gregorian calendar, the twelve-month system that is used throughout most of the world today. And ever since then, Easter has fallen between March 22 and April 25 of every year. Western Christians celebrate Easter on the first Sunday after every Paschal Full Moon. In actuality, this full moon is not an astronomical occurrence, but a complex series of calculations.