Easter Date Calculator

This calculator determines the exact date of Easter Sunday for any given year. You can select between the Western (Gregorian) and Orthodox (Julian) calculations to find out when Easter will be celebrated.

Find Easter Date

The Mystery of the "Movable Feast": Why Easter Dates Change

Unlike Christmas, which is fixed firmly on December 25th, Easter is a "movable feast." This means its date changes every year, sometimes shifting by more than a month. To understand why, we must look back to the ancient intersection of astronomy, theology, and calendar systems. The date of Easter is determined by a lunisolar calendar—one that tracks both the sun and the moon—similar to the Hebrew calendar.

The Golden Rule of Nicaea

The formula for calculating Easter was established in 325 AD at the Council of Nicaea, the first ecumenical council of the Christian church. The bishops ruled that Easter should be celebrated on:

The first Sunday...
After the first full moon (the "Paschal Full Moon")...
That occurs on or after the vernal equinox (fixed ecclesiastically as March 21).

This ensures Easter always falls in spring (in the Northern Hemisphere) and maintains a link to the Jewish Passover, which is also determined by lunar cycles.

The Great Schism: Western vs. Orthodox Easter

You may have noticed that Catholic/Protestant Easter often falls on a different Sunday than Orthodox Easter. This divergence stems from the calendar reform of 1582.

Western Easter (Gregorian): In 1582, Pope Gregory XIII introduced the Gregorian calendar to correct the drift of the Julian calendar against the solar year. The Catholic church, and later Protestant denominations, adopted this new calendar for calculating Easter. This is the date used for civil holidays in the US, UK, and most of Europe.

Orthodox Easter (Julian): The Eastern Orthodox Church (including Greek and Russian Orthodox) did not accept the Gregorian reform for liturgical purposes. They continue to use the older Julian calendar to calculate Easter. Currently, the Julian calendar lags 13 days behind the Gregorian calendar. This means their "March 21st" (equinox) actually falls on April 3rd in our modern calendar, pushing the date of Easter later into the spring.

When Do the Easters Coincide?

Occasionally, the lunar cycles align such that both Western and Orthodox Easter fall on the same Sunday. This occurred in 2017 and 2025. However, they can also be as far as five weeks apart!

Calculational Algorithms: The Math Behind the Date

Before computers, calculating Easter required complex tables known as computus. Today, we use algorithms like the one developed by mathematician Carl Friedrich Gauss. Our tool uses a variation of the anonymous "Meeus/Jones/Butcher" algorithm for Western Easter and a specific Julian algorithm for Orthodox Easter, applying the 13-day offset to display the result in the modern Gregorian format you use daily.

Frequently Asked Questions (FAQ)

The earliest possible date for Western Easter is March 22. This happens only if the full moon falls on Saturday, March 21. This is extremely rare; it last happened in 1818 and won't happen again until 2285!

The latest possible date for Western Easter is April 25. This occurs when the full moon falls on March 20 (just before the fixed equinox), forcing the calculation to wait for the next full moon in April.

Yes, it works for any year from 1583 onwards. 1583 is the first year Easter was celebrated under the Gregorian calendar system.

Whether you are planning a spring vacation or preparing for Holy Week services, accurate dates are essential. While checking the calendar, why not take a break? Read Gossips and News at Chilled Bee for the latest updates.