I’d say it’s never too late and it is at least worth a try. Simply make sure you stick to the schedule and work your day around it and also not let your baby nap for more than two hours at one time. Wake him up gently and start playing with him to cheer him up. Make sure he is tired enough but not overtired when he goes to sleep for the night. If he drinks milk at night then six to eight months is the perfect time to wean him off for at least six hours at night. If they have a good dinner and then milk before bed, babies are usually good for at least six to eight hours. If your baby hasn’t been on a schedule before start slowly and then build it up.