Easter is a movable feast: it can land anywhere in a five-week window, and Western and Orthodox churches often celebrate on different Sundays. This calculator runs the church’s own arithmetic — the computus — for any year from 1583. It gives both Easter Sundays, lists the feasts that move with Easter (Ash Wednesday, Good Friday, Ascension, Pentecost and more) and shows every step.
How to use the Easter date calculator
- Enter a year from 1583 to 9999.
- Choose how many years to list in the comparison table.
- Read Western Easter on the tape, with Orthodox Easter and the gap between them underneath.
- The tables give the full set of movable feasts for the year and a multi-year list of both Easters.
The Easter rule
Since the Council of Nicaea in AD 325, Easter has been the first Sunday after the paschal full moon — the first ecclesiastical full moon on or after March 21. The church does not observe the real moon. It uses a 19-year table based on the Metonic cycle (19 years are almost exactly 235 lunar months), with century corrections added for the Gregorian reform of 1582.
The Anonymous Gregorian algorithm
This compact version of the Gregorian computus was published in 1876 and is often credited to Meeus, Jones and Butcher. All divisions are whole-number divisions:
Roughly, h locates the paschal full moon and l counts forward to the next Sunday.
Orthodox Easter
The Orthodox date uses Meeus’s Julian-calendar algorithm — d = (19 × (Y mod 19) + 15) mod 30 and e = (2 × (Y mod 4) + 4 × (Y mod 7) − d + 34) mod 7 — which gives a Julian-calendar date. Adding ⌊Y/100⌋ − ⌊Y/400⌋ − 2 days (13 days for 1900–2099) converts it to the Gregorian calendar.
Worked example: 2027
Western: a = 13, b = 20, c = 27, d = 5, e = 0, f = 1, g = 6, h = 1, i = 6, k = 3, l = 5, m = 0. Then (1 + 5 + 114) = 120, so month = ⌊120/31⌋ = 3 and day = (120 mod 31) + 1 = 28 → Sunday, March 28, 2027.
Orthodox: d = 22 and e = 6 give April 19 on the Julian calendar; adding 13 days gives Sunday, May 2, 2027, five weeks after the Western date.
Easter dates 2025–2035
| Year | Western Easter | Orthodox Easter |
|---|---|---|
| 2025 | April 20 | April 20 |
| 2026 | April 5 | April 12 |
| 2027 | March 28 | May 2 |
| 2028 | April 16 | April 16 |
| 2029 | April 1 | April 8 |
| 2030 | April 21 | April 28 |
| 2031 | April 13 | April 13 |
| 2032 | March 28 | May 2 |
| 2033 | April 17 | April 24 |
| 2034 | April 9 | April 9 |
| 2035 | March 25 | April 29 |
Feasts that move with Easter
Ash Wednesday comes 46 days before Easter (40 fasting days plus six Sundays), Palm Sunday a week before, Good Friday two days before, Ascension Day 39 days after, Pentecost 49 days after and Corpus Christi 60 days after. In the Orthodox calendar, Great Lent begins on Clean Monday, 48 days before Orthodox Easter.
To count down to Easter or any holiday, use the days until calculator. The moon phase calculator shows the astronomical full moon, which can differ from the church’s tabular one, and the printable calendar can mark Easter among other observances.
Frequently asked questions
How is the date of Easter determined?
Western churches celebrate Easter on the first Sunday after the ecclesiastical full moon that falls on or after March 21. That full moon comes from fixed church tables (the computus), not from the astronomical moon, so it can differ from the real full moon by a day or two.
What are the earliest and latest possible dates for Easter?
Western Easter can fall from March 22 to April 25. The last March 22 Easter was in 1818 and the next is in 2285; April 25 last happened in 1943 and comes again in 2038.
Why is Orthodox Easter usually later?
Orthodox churches use the same kind of rule but apply it on the Julian calendar, which now runs 13 days behind the Gregorian calendar, and with older lunar tables. As a result Orthodox Easter matches Western Easter in some years and is one, four or five weeks later in others.
When is Easter 2027?
Western Easter 2027 is Sunday, March 28, 2027. Orthodox Easter is five weeks later, on Sunday, May 2, 2027.
Which years does the calculator support?
Any year from 1583, the first full year of the Gregorian calendar, to 9999. Orthodox dates are converted to the Gregorian calendar with the correct offset for each century.