When I hear diari(z/s)e, I think of making a notation in my diary/agenda/calendar/scheduler for a future date, to remind me to do something then. I've always loved the term tickler system to describe this system (in law school, they kept telling us to make sure we had a good tickler system in place, so as not to miss limitation periods, for example). I guess tickling or ticklering something just sounds too frivolous for the big bad world of business, but I like it!