what do i do?

My boyfriend stays up until four or five in the morning and then wakes up at three in the afternoon. even when we're supposed to spend the day together, he sleeps all day long and then expects me to be able to stay up all night to hang out. I usually end up falling asleep while we're watching a movie, and then feel bad when he has to leave. I hate not knowing what the day's schedule is, and he knows that, but it's nearly impossible to get him to wake up before noon.

Any advice as to how I can get him to realize that his sleeping all day prevents me from getting stuff done during the day, as well as screwing up my sleep is appreciated.