My advice is to change his bedtime. If seeing his father every night before going to bed is that important to him, I would not deny a child the comfort of just a brief visit with his Dad. He can make up for the lost sleep with a longer nap, but these moments with his father can never be replaced or made up for. How about giving him a little longer nap in the afternoon, so he can stay up to see Daddy. Or, put him in his bed and tell him that he doesn't have to go to sleep, he can play quietly or look at a book. That way he will be resting. The promise, that must be kept, is that Daddy will come in and tuck him in as soon as he gets home every night. Maybe Daddy can read him a little story before going to sleep. But, please do not prevent him from continuing to form that bond between father and child. The psychological harm from that far outweighs the benefits of forcing him to go to bed at your schedule. He's telling you that his father is very dear to him. Please listen to him.