Open Veils · Answer
How does the medieval Easter table encode a date?
The Easter table is a compressed cosmological cipher encoding three interlocking cycles — the 19-year Metonic lunar cycle, the 28-year solar/weekday cycle, and their 532-year combined period. Dionysius Exiguus built this into a living calendrical machine in 525 AD that simultaneously smuggled in a new year-numbering system. Bede then weaponized that system to anchor all of Western historical time.
Evidence
- In 525 AD, Dionysius Exiguus constructed a 95-year Easter table covering Anno Domini 532–626 — the first documented use of the AD era.
- The core encoding mechanism rests on the Golden Number — each year's position within the 19-year Metonic cycle, calculated as (year mod 19) + 1.
- The second layer is the Ferial Regular — the weekday displacement of that Paschal Full Moon from the concurrent, meaning the weekday of 24 March in that year.
- Bede's 8th-century De temporum ratione, documented in The Reckoning of Time, extended Dionysius' mechanism into a full 532-year Great Cycle (19 × 28), after which all dates repeat exactly.
- According to the Wikipedia record of Dionysius' table, column A introduced the Christian era while column G encoded the final Easter Sunday dates; the two columns together formed a dual-output machine, one liturgical and one chronological.