I have a calendar fixation, but only with VERY specific and dates in my own life - some important, some unimportant which I just happened to notice the time or something, or think of it. I can't do calendar calculation stuff, I just remember the precise date, and often time, down to the minute.
For example, on Wednesday, December 28th, 2011, at 7:28 PM, me and my (then) girlfriend (now ex) were checking out at a store. I took my turn checking out at 7:31 PM. This one is just an example of a totally boring moment being remembered.
Another one, along the same vein, Friday, September 2nd, 2011, we went to the state fair. That one I remember just because it was a pretty awesome day. It looked like it was going to rain on us, but once we got out there, and parked at 4:47 PM, there was nothing but sunshine. I could go into even more detail if you want, about which times we did certain things that day. We left at 9:32, even though we intended to leave at 9:15, simply because we wanted to find this one mini doughnut stand - I even remember the color of the token they gave us to exchange on the other side of the stand for the doughnuts - white, and it was really just a plastic poker chip.