Being a teacher, I'm sure we all use one. What kind(s) do you use? I'd feel lost w/o my calendar. I love those monthly planners in the spiral bendable book format. I prefer seeing the whole month at once, NOT just a week. And a nice box for each date to write a few things in. A cute wall calendar w/ puppy pictures is also nice to hang up (in the classroom). Plus, I like having a mini-calendar for my purse. If I had my own desk at work, I like those desk calendars. (BTW, I don't input any appts in my cell phone.) I never have to buy my own calendar/planner. My mom can ge it for me from her work.