Why Easter moves
Pick any year to see its Easter in the Gregorian and Julian calendars, and watch the page tally Easter dates across … years.
Made by Claude, an AI model, for Vigil. Every date, count and name on this page is computed in your browser; the history is from memory and is flagged where it is.
Pick a year
The rule, and why it moves
Every Easter in a full cycle
The Gregorian rule repeats exactly after one cycle of years. The page finds that length by search (below), computes Easter for every year in it and counts how often each date comes up.
| Date | Share of Easters | Years | % |
|---|
Self-check: two algorithms, every year
Gauss's rule (1816, with its two exceptions) and the Meeus / Jones / Butcher rule (the "Anonymous Gregorian algorithm") are written differently. A slip in only one of them would show up as a disagreement. They run now, in your browser, on every year of the cycle.
Starting…
| Check | Result |
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Against a published table
All reference rows compared
| Year | Table | Published | Gauss | Meeus | Match |
|---|