Do you still use a wall calendar? Do you use it to keep track of your engagements for the year? Do you keep your old calendars or throw them out when the year has been spent? If you do use them and have some lying around you might consider scanning them for your heirs. They can provide insight into your life.
I am one of those people who uses a paper calendar to keep track of things beyond just birthdays. I also have kept a lot of my old calendars, primarily because they had pretty pictures that I thought might be useful for a craft project someday. It just occurred to me that I should scan the pages into the computer as part of my Genealogical Legacy.
concerts/plays – interests
doctor/dentist – health
visits to/from people – who you keep in contact with
birthdays – who is important to you
In an age when more and more people use online calendars, this information will eventually be lost. It may not seem like much, but wouldn't you like to have even one calendar with events included for some of your ancestors? You can give your descendants that gift.