23 April 2022

When is this year's 'Celtic' Easter

 Can anyone tell me when the 'Celtic', or Irish, Easter is this year? And, of course, why?

If an answer depends on the 1987 Peritia article, I would be glad to have a link.


4 comments:

Éamonn said...

I have no idea about the answer to your question but the Peritia article you mention might be this one: https://www.dropbox.com/s/o71ypig1behwjyu/Irish%20Easter%20Table%20J.Peri.3.165.pdf?dl=0

frjustin said...

"With the abandonment of the Irish Easter on Iona in 716 AD, the 84-year table was discarded and all trace of it was lost, until its rediscovery in 1984. The recovery of that long-lost table after more than 1200 years and its subsequent reconstruction and restoration, have enabled modern scholars to calculate the historical Easter dates of the Early Irish Church."
https://www.rte.ie/brainstorm/2018/0329/950886-how-the-irish-helped-to-create-easter-sunday/

There is a year-by-year reconstruction of the Irish 84-year Table in a document scanned for pdf format. Table 2 lists a reconstructed "latercus" of Irish Easters for the years AD 438 to AD 521, including cyclic numbers 1 through 84, as well as the Epact, Paschal Date and Full Moon. However its application to this year is quite beyond me!
https://www.mgh-bibliothek.de/dokumente/a/a149668.pdf

Jhayes said...

“ The dispute between the Celtic and Roman churches was in determining when the third week of March occurred: whether between the fourteenth and twentieth of the month, as the Celtic church believed, or between the fifteenth and twenty first, as Bede insisted.”

And

“ In quoting a long letter from Ceolfrid to the king of the Picts, Bede reiterates the Roman church's position on the observation of Easter. It was to be celebrated in the first month of the year, in the third week of that month, and on the first Sunday of that week, that is, the first Sunday after the first full moon following the vernal equinox on March 21.

[Quoting Bede] "Therefore, whatever moon is at the full before the equinox, when it falls on the fourteenth or fifteenth day, rightly belongs to the last month of the preceding year, and consequently is not suitable for keeping Easter. But the full moon falling either on or after the equinox itself certainly belongs to the first month; on it the ancients used to keep the Passover, and when Sunday comes, we should keep Easter.... Whoever argues, therefore, that the Paschal full moon can occur before the equinox, disagrees with the teaching of the scriptures in the observance of our highest mysteries, and allies himself with those who believe that they can be saved without the assistance of Christ's grace."[end Bede]

“This contention between the Celtic and Roman churches as to the proper observance of Easter was a matter that would not be resolved until the Synod of Whitby in AD 664, when King Oswy of Northumbria decided in favor of the Roman church. That the situation was intolerable can be seen in Oswy celebrating Easter according to the Celtic custom, while his wife still was observing Palm Sunday.”

https://penelope.uchicago.edu/~grout/encyclopaedia_romana/britannia/anglo-saxon/earlychurch/paschal.html

See the article for more quotes from Bede

Andrew Malton said...

http://www.mgh-bibliothek.de/dokumente/a/a149668.pdf

https://www.irishphilosophy.com/2018/04/01/irish-computus/#fn-9077-8

But also more recently

The Munich Computus and the 84 (14)-year Easter reckoning
Immo Warntjes
Proceedings of the Royal Irish Academy: Archaeology, Culture, History, Literature
Vol. 107C (2007), pp. 31-85

I can't find an implementation of it that answers the actual question, though. And the question might be ambiguous: is there a unique Irish or Celtic computus?