The afternoon hunt starts at 12:01 pm silly. Duh, I mean afternoon is like short for after noon.

Just kidding. I'm convinced that deer can be found at any time of day but like you I just don't have the attention span to sit all day (not to mention my back won't allow me to stay in a stand that long. Now, during the early season I usually hunt till 10 or 11 then get back in my stand around 4. As the weather gets colder and the rut nears though I'll force myself to spend more time in stand because daytime activity will increase tremendously.