I have the same problem with my Jacks, they are now "conditioned" into getting up at the same time each day, and they do not know my "work rota". The only way i can overcome this is just to let them out for a pee then i go back to bed. There body clock is used to functioning at the set time as when we house train them they follow a strict routine and it is this that has "conditioned them into the routine". sorry if this does not help you with you problem.