JdeBP2h ago

The 1750 #UKLaw rule for calculating the date of #Easter breaks down quite simply.

The New Testament account is that Jesus rose from the dead on the day after the Sabbath, i.e. the Sunday (the Sabbath being Saturday), that followed Passover.

So what's the date of #Passover? It's the fourteenth day of Nisan, which is the first (ecclesiastical) month of the Hebrew luni-solar calendar.

Hebrew calendar months (nominally) begin at the new moon, so the 14th day is (approximately) the time of the full moon.

So when does #Nisan start? It has all been done with tables for about 16 centuries, but the underlying aim was to tie it to the vernal equinox.

Hence expressing all of this with the religions taken out: Easter is the first Sunday after the first full moon after the vernal equinox.

And because the Gregorian Calendar aimed to stabilize the dates of the equinoxes, taking even some of the #astronomy out of the rule gets this last part turned into "after the 21st of March".

#Pascha

Show threadJdeBP

If you go and read the Calendar (New Style) Act 1750, you'll find that there the "moon" is not an astronomical one. As mentioned, the Hebrew calendar began using lookup tables about 16 centuries ago. It had all been tables for centuries by 1750.

The 1750 Act laid out tables for calculating, using a system of 'Dominical letters' and 'Golden numbers', the date of Easter.

Basically, there's a notional 'full moon' here that is calculated, not observed by looking at Luna. Hence how the drafters of the Act were able to construct tables that went up to the year 2199.

https://legislation.gov.uk/apgb/Geo2/24/23/section/6

#Passover #Pascha #Nisan #astronomy #UKLaw #Easter

Calendar (New Style) Act 1750

An Act for regulating the Commencement of the Year, and for correcting the Calendar now in use.

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