How to use it
- Type a year between 1583 and 4099.
- Choose Western or Orthodox.
- Read the date of Easter Sunday and the related dates. All dates are in the Gregorian calendar, the one used in civil life almost everywhere.
How it works
Western Easter uses the anonymous Gregorian algorithm (often credited to Meeus, Jones and Butcher), which reproduces the church’s table of ecclesiastical full moons with whole-number arithmetic. It is valid for every year after the Gregorian calendar began, which is why the range starts at 1583.
Orthodox Easter uses Meeus’s Julian algorithm, which gives the date in the Julian calendar. The result is then moved to the Gregorian calendar by adding the difference between the calendars: 13 days from 1900 to 2099, growing by one day at each century year that is not divisible by 400. Most Orthodox churches keep this reckoning for Easter, even those that use the Gregorian-style calendar for fixed feasts.
The other feasts are plain offsets from Easter Sunday: Palm Sunday −7 days, Good Friday −2, Ascension Day +39 and Pentecost +49. Ash Wednesday (−46) is shown for Western Easter and Clean Monday (−48) for Orthodox.
Worked example
For 2026 the Western algorithm gives 5 April. Ash Wednesday is 46 days earlier, on 18 February; Ascension Day is 39 days later, on 14 May; Pentecost is on 24 May. The Julian algorithm gives 30 March, and 13 days later is 12 April, so Orthodox Easter is a week after Western Easter that year.
Good to know
- Some countries and churches mark the dates differently for local reasons. If a date matters for a legal or religious purpose, confirm it with your own church or the official calendar.
- Public holidays such as Easter Monday or Good Friday depend on the country; this tool gives only the feast dates.