When is Easter? Find the date for any year
Easter Sunday is the most important movable feast in the Christian calendar, and its date shifts every year because it is tied to the moon rather than a fixed day. By the rule set at the First Council of Nicaea (325 AD), Easter falls on the first Sunday after the first ecclesiastical full moon on or after 21 March. The Western (Catholic and Protestant) churches compute it on the Gregorian calendar, while the Eastern Orthodox churches use the older Julian computus — so the two dates usually differ by one to five weeks.
The ecclesiastical full moon: not the same as the astronomical full moon
The phrase “full moon” in the Easter rule does not mean the astronomical full moon you might see in a sky almanac. The ecclesiastical full moon is a calculated date based on a 19-year cycle (the Metonic cycle), fixed by tables agreed upon by the church rather than updated from astronomical observation. The two can differ by a day or two.
This distinction matters for edge-case years where the astronomical full moon falls on a Saturday (the day before a Sunday), but the ecclesiastical tables place the full moon on the following Sunday — pushing the computus full moon forward and therefore Easter forward by a week. The algorithm this tool uses follows the ecclesiastical definition faithfully, which is why the dates it produces match official published Easter tables rather than astronomical predictions.
How it works
This tool uses pure arithmetic — no lookup tables. For Western Easter it runs the Anonymous Gregorian algorithm (Meeus/Jones/Butcher): from the year it derives the golden number (year mod 19), the century, leap-cycle corrections, the epact and a weekday offset, then combines them into a month and day. For Orthodox Easter it runs Meeus’s Julian algorithm to get the Julian-calendar date, then adds a 13-day offset (valid for 1900–2099) to convert it to the Gregorian calendar. The weekday is read directly from a UTC date so the result always lands on a Sunday.
Example
Enter 2026 with the Western tradition and the algorithm returns April 5, 2026, a Sunday. Switch to Eastern Orthodox for the same year and you get April 12, 2026 — one week later, because the Julian computus places the paschal full moon differently.
| Year | Western Easter | Orthodox Easter |
|---|---|---|
| 2025 | April 20 | April 20 (same) |
| 2026 | April 5 | April 12 |
| 2027 | March 28 | May 2 |
Everything is computed locally in your browser. No year or input ever leaves your device.
Planning around Easter: public holidays downstream
Easter Sunday itself is only the first date in a cluster of public holidays across Christian-heritage countries. Knowing Easter’s date lets you derive the whole Easter weekend and the weeks around it:
| Holiday | Relationship to Easter Sunday |
|---|---|
| Good Friday | 2 days before (Easter Sunday − 2) |
| Holy Saturday / Easter Eve | 1 day before |
| Easter Sunday | The computed date |
| Easter Monday | 1 day after (observed in most EU countries, UK, Australia) |
| Ascension Thursday | Easter + 39 days |
| Whit Sunday (Pentecost) | Easter + 49 days |
| Whit Monday | Easter + 50 days (observed in many EU countries) |
For travel, school-break, and business planning, Easter Sunday’s date anchors all of these. A shift of even one week in Easter’s date — which happens frequently given the variable algorithm — moves every downstream holiday with it.
Why Easter date matters for software
Calendar libraries that naively define public holidays as fixed month-day combinations will fail for Easter-dependent holidays. Libraries that implement the computus correctly (or look up published tables) will correctly compute Good Friday, Easter Monday, and Ascension. When building HR, payroll, or scheduling software for markets with Easter-based public holidays, always use a library that models the computus rather than hardcoding dates year by year.