I'd say anytime I'm in the mood and I'm in the mood for a movie mostly late at night. I'm not really an early morning movie person, too bright and too noisy.
__________________ "Have you crashed your Windows today?"
A working person like myself probably prefer watching movies at night. But I guess I can't do it often because I might be tired already at the end of the day. So, weekends will be the best time for me!