This intermediate challenge is a little mathier than the average, but that's not as biga deal as one might imagine because of the fact that algorithms for figuring out when Easter Sunday falls are literally hundreds of years old and (obviously) well-publicized. My initial solution for this (written in C#) actually takes advantage of a random personal website somewhere and System.Net.WebClient to load and parse the required data without doing any actual calculations. It's amazing what you can achieve with two regular expressions, some linq, and a little stubbornness.
This solution instead makes use of an anonymous Gregorian algorithm to achieve the intended result, calculating the month and day of Easter Sunday via some of the most arcane mathematics imaginable.
Of course, the challenge output portion of today's assignment is a little bit more annoying to deal with in bash/linux/etc., but--in the spirit of learning new things--I have written a bash script that carries out the necessary calculations. (Actually, I have changed it to a zsh script because I've decided to say screw bash and just install zsh on my machines, but it still has a .sh extension. I suppose this may be wrong.)