I know this is an older post, but in case anyone is doing a search on how to calculate Easter Sunday, here is how you do it. You'll need a few Composes...
I have a Compose called Year that holds the year that I'm trying to find the date.
a
mod(outputs('Year'), 19)
b
div(outputs('Year'), 100)
c
mod(outputs('Year'), 100)
d
div(outputs('b'), 4)
e
mod(outputs('b'), 4)
g
div(add(mul(8, outputs('b')), 13), 25)
h
mod(add(sub(sub(add(mul(19, outputs('a')), outputs('b')), outputs('d')), outputs('g')), 15), 30)
i
div(outputs('c'), 4)
k
mod(outputs('c'), 4)
l
mod(sub(sub(add(add(32, mul(2, outputs('e'))), mul(2, outputs('i'))), outputs('h')), outputs('k')), 7)
m
div(add(add(outputs('a'), mul(11,outputs('h'))), mul(19, outputs('l'))), 433)
n
div(add(sub(add(outputs('h'), outputs('l')), mul(7, outputs('m'))), 90), 25)
p
mod(add(add(sub(add(outputs('h'), outputs('l')), mul(7, outputs('m'))), mul(33, outputs('n'))), 19), 32)
Month = n
Day = p
My Easter Days are string variables:
varEasterSunday
outputs('n')/outputs('p')/outputs('Year')
varEasterMonday
addDays(variables('varEasterSunday'), 1)
varGoodFriday
addDays(variables('varEasterSunday'), -2)
I hope that this helps someone out there.
Source for equation: https://en.wikipedia.org/wiki/Date_of_Easter#Algorithms
