This entry was published at least two years ago (originally posted on March 28, 2009). Since that time the information may have become outdated or my beliefs may have changed (in general, assume a more open and liberal current viewpoint). A fuller disclaimer is available.
I’ve just resurrected an old project, using Wikipedia’s list of unofficial observances to create a calendar file (in .ics format) suitable for download and direct import or subscription in iCal, Outlook, Google Calendar, or (as far as I know) any other reputable calendar program. Here’s the link — drop that into your calendar, and never miss another Pi Day, Yellow Pig’s Day, or Day of the Ninja again (here’s an HTML version if you just want to look at it online)!