How do I keep myself from getting sleepy during the day?

When I'm trying to re-establish my sleep/wake schedule, I do anything that will keep me out of bed. For example, even if I'm really sleepy, I can still play computer games and eat. I know, not particularly productive, but at least I stay out of bed. I let myself do whatever I want for a few days, as long as I don't crawl back into bed. I find that after a few days, my brain gets used to the idea that I am going to be awake between so-and-so hours. It does actually work!! All the best!!