The calendar serves both as an appointment book, and at the end of the day, a place to briefly recount the events of that day (some would call it a diary). It becomes a wonderful back-up when my husband's computer calendar isn't accessible since we often travel in places where on-line access is limited. Similarly, my husband often uses what I've written in the calendar to help remind him of the names of places he has photographed that day. I can't tell you how many times I have been able to look at past years' calendars to confirm (or disconfirm) some event.
