First off, happy belated pi day! Second, someone at work yesterday noted that every month has an ides, but it’s not always on the same day. That led me to this Wikipedia article, which proves not only that I have been pathetically ignorant of the calendar’s origins, but that I’ve not even had a good excuse for being so.
For example, September through December are so clearly enumerations that I really can’t understand how I didn’t get it before, only that they no longer correspond to the right numbers.
The article’s a quick read, and we’ll worth it. One last thing – just like the ides is the middle, kalends is the first day of the month.