1. What is Easter Sunday?

Easter Sunday is the most important Christian holiday, celebrating the resurrection of Jesus Christ. Unlike fixed-date holidays, Easter's date changes each year based on a complex calculation tied to astronomical events.

2. How is Easter Date Calculated?

Easter Sunday is determined as the first Sunday after the first full moon occurring on or after the vernal (spring) equinox. The calculation uses:

Key components:

• Vernal Equinox: Fixed at March 21 for calculation purposes
• Full Moon: Ecclesiastical approximation of astronomical full moon
• Sunday: The following Sunday after the Paschal Full Moon

Note: The Gregorian calendar calculation uses the Gauss algorithm, which provides the same results as the astronomical method for most years.

3. Historical Background

Details: The current calculation method was established by the First Council of Nicaea in 325 AD and refined with the Gregorian calendar reform in 1582. Western Christian churches use the Gregorian calendar, while some Eastern churches still use the Julian calendar.

4. Using the Calculator

Instructions: Simply enter any year between 1583 (when Gregorian calendar was introduced) and 9999, then click Calculate to see the date of Easter Sunday for that year.

5. Frequently Asked Questions (FAQ)

Q1: Why does Easter's date change every year?
A: Easter is tied to lunar cycles (full moon) and the spring equinox, which don't align perfectly with our solar calendar.

Q2: What's the earliest possible Easter date?
A: March 22 (last occurred in 1818, will next occur in 2285)

Q3: What's the latest possible Easter date?
A: April 25 (last occurred in 1943, will next occur in 2038)

Q4: Why do Eastern and Western Easter sometimes differ?
A: Different churches use different calendars (Gregorian vs Julian) and different calculation methods for the full moon.

Q5: How far in advance can Easter be calculated?
A: The calculation method works for any year, though astronomical variations may require adjustments over very long timescales.