Easter.exe, Version 1.00 Calculate the date of Easter Sunday for the specified year Usage: Easter.exe [ year [ format ] ] Where: year is the year to calculate Easter date for (default: current year; see notes for before 100 AD) format is the output format for the returned date: either "short", "long" or a combination of 6..10 "y", "M", "d" characters, hyphens, forward slashes, dots and/or spaces (default: "yyyy-MM-dd") Notes: Easter Sunday is at the first Sunday after the first full moon at or after the Spring equinox, which for Easter calculations is assumed to be always at March 21. Years before 100 AD will be interpreted as 2000 + specified year. The program's return code equals the calculated date's DayOfYear value, or -1 in case of (command line) errors. Credits: Easter calculation explained: https://www.timeanddate.com/calendar/determining-easter-date.html Written by Rob van der Woude https://www.robvanderwoude.com