Beautiful job.  I found myself wanting to know more and more!  There's a typo up there.  You said one of the calendar counted out 260 days and the other 365.  I'm only mentioning it because I know you can fix it.

I reckon with all those different counting systems and months and stuff, they didn't use their calendar the same way we do; to keep track of mundane things like doctor appointments and when the next Time Capsule Project is due?  (That really is a question, honest.)