This is some advice my therapist gave me, I am not sure how much it applies to your situation but maybe it will be some help. She told me that if you have something you need to get done instead of giving yourself all day Saturday to get it done, give yourself a smaller time frame. Such as giving yourself from 10 a.m. to 11 a.m. to get something done you think will take you about an hour or less. Then at 11 a.m. plan to go out to lunch with your friends or something. This in a way "forces" you to sit down and do whatever you are trying to get done in that hour time frame. Then it gets done and you are not still procrastinating about doing it at 8:00 p.m. on Saturday night. I don't know if this is helpful, but it has helped me out to a certain extent in motivating myself.