Unlike Christmas which is always on December 25, the date of Easter Sunday varies from year to year. However, there are algorithms that allow you to calculate this date for any past, present or future year.
The algorithm that was implemented in this module is described here and its results were successfully compared to the 518 Easter Sunday dates that can be found on these webpages:
- http://palluy.fr/index.php?page=1583-a-1600-apres-paques
- https://www.census.gov/data/software/x13as/genhol/easter-dates.html
Nim +2.0.0
Nim standard library only.
Install easter using nimble:
nimble install easter
or add a dependency to the .nimble file of your project:
requires "easter >= 0.1.0"
and start using it:
import easter
let easterSunday2054 = gregorianEasterSundayMMDD(2054)
# the 'gregorianEasterSundayMMDD' proc returns an Option
# for the reasons given in the documentation
doAssert: easterSunday2054 is Option[(int, int)]
doAssert: get(easterSunday2054) == (month: 3, monthday: 29)