Its know that certain times of the day are better for asking questions than others. Sometimes someone has a very strange question, or has another good reason to game the time the question gets asked. Since the result is good for the user (gets the best possible anwer for their question), and assumeable best for the community since it would lead to better content overall if more hard or obscure questions got answered.
Edit As an alternative, how about the ability to queue up a question have it entered into the system, but not have it appear on the site until a button is pushed later. This way someone has to be on the site when the question goes live, but they can write it up ahead of time.
So is such a feature desirable for stackoverflow?