@sundogplanets

I never understood why it always changes.

@grb090423 Backwards compatibility. It's tied to a Jewish holiday, and the Jewish lunisolar calendar is built radically differently from the solar-dominant Roman calendars that grew dominant in the Christian parts of Europe.

@sundogplanets

@riley @sundogplanets

Thank you for explaining this. I did not know 👍🙂

@grb090423 In the early days of the Christianity, the Easter date could be determined in Rome, and just, effectively, mailed to wherever there were Christian congregations. But by the late 400s / early 500s, the Roman Empire was in such a delapidated state that reliable mailing started to be an increasing problem, so various offline methods for the Easter determination were considered. The officially adopted one was eventually based on an algorithm developed by one Dionysios Exiguus, or Dennis the Geek, potentially partly because of its another important benefit: it allowed the steps to be unambiguously independently verified, and mistakes caught. (There were a couple of embarrassing mistakes in some Easter tables that the early Popes published. Big scandals in their days, because holidays were Serious Business. Literally.)

@sundogplanets

@riley @sundogplanets

You are educating me! I can definitely say TIL.

Dennis the geek... Is that real?!

Do you know so much about this because you have studied it?

@grb090423

It's sort-of real. 

Dionysios was once a popular Greek name, derived from the name of the ancient Greek deity of drinking and being merry. The modern English Dennis is an adaptation of it, the same way a lot of modern English names are adaptations of Greek names poularised by Christianity's spread. This particular Dionysios was a monk known for being small and humble ('Exiguus' literally means 'Humble'), and, well, also for enjoying computing things. Hence, I submit that 'the Geek' is a defensible translation of his Greek nickname.  

I know these things because Knuth's The Art of Computer Programming includes a passage about the Computus, as an example of an early elaborate algorithm, and, being an #ADHD kid, I promptly descended into the rabbit-hole.

@sundogplanets