Too much sleep

This is not about me, its about my boyfriend. All he seems to do is sleep. He works as a door man in town so it is natural that he would sleep into the day at weekends having got home and 4am. But in my opinion he sleeps far too much, i sleep quite a bit, but no where near as much as him. For instance today i went to bed at 2am and got up and 10am, (8 hours i pretty much fine for me) no idea what time he got up, but he didn't work last night so unless he stayed up for no reason he should have had enough to sleep to get up at a reasonable time, he came over at 2pm read the paper and is now in my bed sleeping and has been since about 3pm maybe a bit before that. I understand he has a job and uni work but surely this amount of sleep in not healthy? I've tried talking to him but he just gets annoyed and says he has late job and he's tired and needs to sleep. What can i do? How can i make him realise that so much sleep is not good for him.