If your question is “do most ALZ patients sleep until the afternoon.”, then the answer is “No.” (since there is always a “however”) However, the range of sleeping patterns for ALZ patients varies tremendously and the sleeping patterns change over time.

I realize I haven’t given you any useful information since there is no norm for sleep time among ALZ patients. Perhaps a better question is “should I be concerned if my husband sleeps until the afternoon?” My answer is, again, “No.” My wife sleeps a solid 8 hours each night and still manages naps of 2 hours or more during the daytime. However, my wife takes prescription narcotics to help her sleep.

Perhaps you could keep a log of your husband’s sleep time over a one week period and present that log to your husband’s specialist (neurologist?) for review.

Having the disease I find taking naps makes my mind clearer. So for me naps are a very good thing

My partner sleeps usually until noon and often naps In the afternoon. It seems to be part of the disease
ramifications.

I find that if my husband takes naps, he's ready to get up at 5:30 in the morning, which means I have to, too.
I try to squeeze a nap in when he does, but I have so many things to take care of, I mostly don't GRT to it.

Agree. Really there is very little, if anything, that can be done for Alzheimer's patients.