Back to the basics. Make yourself a schedule and stick to it, after that it becomes a natural habit since your body clock will then be in a normal state where it adheres to an enforced, self-imposed discipline.
To go and watch the latest/last Harry Potter movie before my best friend comes up to watch it with me on the weekend or not?
If you can see this it means I'm posting outside of the mapping forums and you should take anything I said with heaps of salt, or as purely intended for humor.