Christmas is always on December 25, but Easter can fall anywhere between March 22 and April 25. The reason lies in a decision made over 1,700 years ago and a calculation that has been refined ever since. This guide explains the rule, the history and how to work out the date yourself.
The rule in one sentence
In Western churches, Easter Sunday is the first Sunday after the first full moon on or after the spring equinox. The equinox is treated as fixed on March 21, and the full moon is not the astronomical one but a calculated one from church tables, called the ecclesiastical full moon.
That is why the date moves. The cycle of the moon and the cycle of the weekdays do not line up with the solar year, and the combination repeats only after many years.
Why the rule exists
The Gospels place Jesus's crucifixion and resurrection around the Jewish Passover, which is tied to the full moon of the spring month of Nisan. In the early centuries different Christian communities celebrated on different days, and the Council of Nicaea in the year 325 decided that Easter should be held on a Sunday and not be tied to the Jewish calendar.
The decision to use the equinox and the full moon was a way of keeping the celebration in spring and linked to Passover without depending on the Jewish calendar. The detailed calculation was left to astronomers in Alexandria and later in Rome.
Earliest and latest dates
Because the equinox is fixed at March 21 and the full moon can fall on that day, the earliest possible Easter is March 22. If the ecclesiastical full moon falls on a Sunday, Easter is the Sunday after, a week later. The latest date therefore comes when the full moon falls on Sunday, April 18, which pushes Easter to April 25.
Within that range, some dates are far more common than others, and a few, like March 22, are extremely rare. The earliest Easter of the 21st century was on March 23, 2008, and an Easter as early as March 22 next occurs in 2285.
The next Easter dates
Here are the dates for the coming years, calculated with the Gregorian rules:
- 2026: Sunday, April 5, 2026
- 2027: Sunday, March 28, 2027
- 2028: Sunday, April 16, 2028
- 2029: Sunday, April 1, 2029
- 2030: Sunday, April 21, 2030
A worked example: Easter 2026
The Gauss method, in the version published by Meeus, Jones and Butcher, turns the year into a date with whole-number arithmetic. For 2026 the steps are as follows. Let the year be 2026.
- a = 2026 mod 19 = 12 (the position in the 19-year cycle of the moon)
- b = 20 and c = 26 (the century and the year within it)
- d = 5 and e = 0 (the century divided by 4, and its remainder)
- f = 1 and g = 6 (small corrections for the Gregorian calendar and the moon)
- h = (19a + b − d − g + 15) mod 30 = 12 (the days from March 21 to the full moon)
- i = 6 and k = 2 (the year in the century divided by 4, and its remainder)
- l = (32 + 2e + 2i − h − k) mod 7 = 2 (the days from the full moon to the next Sunday)
- m = 0 (a rare correction)
The month is (h + l − 7m + 114) divided by 31, which is 4, so April, and the day is the remainder plus one, which is 5. Easter 2026 is April 5.
The days that depend on Easter
Easter fixes many other dates in the church year. Counting from Easter Sunday:
- Ash Wednesday is 46 days before, the start of Lent.
- Palm Sunday is 7 days before, Maundy Thursday 3 days before and Good Friday 2 days before.
- Easter Monday is 1 day after.
- Ascension Day is 39 days after, always on a Thursday.
- Pentecost (Whit Sunday) is 49 days after, and Whit Monday 50 days after.
In countries where these are public holidays, such as Norway, an early or late Easter moves a whole block of days off through the spring.
Eastern Orthodox Easter
Most Orthodox churches still calculate Easter using the old Julian calendar. The Julian calendar is now 13 days behind the Gregorian one, and its table for the full moon differs, so Orthodox Easter is usually later. In some years, such as 2025, the two dates coincide, and in other years they are up to five weeks apart.
There have been repeated proposals to agree on a common date, and some churches have suggested using the astronomical equinox and full moon, but no agreement has been reached.
Why not fix the date?
Proposals to fix Easter on a set Sunday, such as the second Sunday in April, have been discussed for a century. The Second Vatican Council said in 1963 that it would not oppose a fixed date if other churches agreed. Without that agreement the old rule continues.
You can check the exact date for any year with the countdown pages on this site, which calculate Easter for every year you choose.