Sitting Sleepy

Sometimes Calvin gets tired. Really, really tired. When he does, he sometimes falls asleep sitting up in bed with his legs in lotus position. Today Calvin got tired. Really, really tired. Three apple orchards, raspberry picking and a hike through the woods. One warm shower later and Calvin is now asleep, naked in his bed, still wrapped in a towel. He fell asleep at 5:30pm. What time do you think he is going to wake?