You can get a barebones anniversary list of events in The Hobbit and The Lord of the Rings on your Mac. Not immediately obvious how I import it into Calendar.
Slightly more information e.g. what the "cat" command in the terminal means (I know I was dying to know) at The Mac Observer.
UPDATE: Since the above links might die this is a note at what you do. (1) On your Mac open the terminal in Applications/Utilities. (2) Type:
Don't forget the space between "cat" and "/usr…"
(3) Hit return. (4) Enjoy Appendix B.