i agree with 1day that asking your friend would be ideal. however, yes, it is possible that he is losing time and that's making his sleep schedule off. it could be like this, he decides to go to sleep but an alter comes out and decides they want to stay awake, so the body doesn't get any rest and stays tired as a result. but directing your questions to your friend is the best idea b/c multiplicity affects everyone differently, as is the case with most everything in life, and so it could be different for him.

good luck

-shadow