Easter Calculator - Find Easter Sunday Date

Easter Sunday is the most important and ancient feast in the Christian calendar, celebrating the resurrection of Jesus Christ. Unlike fixed holidays such as Christmas, Easter is a moveable feast — its date shifts every year, falling anywhere between 22 March and 25 April. This variability flows from a decision made at the First Council of Nicaea in 325 AD: Easter would be observed on the first Sunday following the Paschal Full Moon, which is defined as the first ecclesiastical full moon occurring on or after the spring equinox of 21 March. Because that definition blends astronomical observation with ecclesiastical rule, calculating the exact date requires more than a simple look-up table. Over the centuries, mathematicians and astronomers devised several algorithms for computing the Paschal Full Moon without consulting actual astronomical tables. The most widely trusted modern formula is the Meeus/Jones/Butcher algorithm, which this calculator implements. The algorithm, developed by Jean Meeus and refined by Ron Jones and Thomas Butcher, works entirely in integer arithmetic. It begins by finding the year's position in the 19-year Metonic cycle (the golden number), which governs how lunar phases repeat relative to the solar calendar. It then applies a series of correction factors — including a century correction that adjusts for the drift of the Gregorian calendar — to pinpoint the Paschal Full Moon. Finally it advances the date to the following Sunday to obtain Easter Sunday. All the moveable feasts shown by this calculator are derived from Easter Sunday by fixed offsets. Ash Wednesday, the start of Lent, falls 46 days before Easter. Palm Sunday marks the beginning of Holy Week, seven days before Easter. Good Friday commemorates the crucifixion two days before Easter. Easter Monday, the day after Easter, is a public holiday in many countries. Ascension Day, celebrating Christ's ascent into heaven, falls 39 days after Easter (always a Thursday). Pentecost, marking the descent of the Holy Spirit, is 49 days after Easter. Trinity Sunday follows one week later, 56 days after Easter. The algorithm is valid for all years in the Gregorian calendar, which was introduced in October 1582 and first applied to Easter calculations from 1583. For years before 1583 a different calculation based on the Julian calendar would be needed, which is why this calculator validates the year input against that lower bound. Beyond religious observance, accurate Easter dates are essential for academic calendar planning in countries where schools follow the church year, for liturgical print production that must be completed months in advance, for retail and travel businesses that plan promotions around the Easter holiday period, and for software systems that need to mark public holidays automatically. This calculator gives planners and developers a fast, reliable reference that requires no subscription or external API.