D.H.
You don't say if you know why this time change happened......did you start doing something that woke him up? Did you used to get up earlier? If the answer is no to the questions, then, what has changed in your sons life? Is he less active because it's winter and he can't expend his energy as much? I would try a couple of things. First I would try to take him out somewhere and let him run......go to the mall, whatever he can find to do. Then see if he sleeps longer. It might be his age, does he take a nap? For how long? If so, can you cut the nap by a bit. Try and see if any of this works. If not, you can find things in his room for him to do for an hour or so while your husband sleeps, or you two can have time together in another part of the house without Daddy, so Daddy can sleep. Quiet time can be coloring, drawing, Mommy reading to him, or other things he might like to do. Maybe some days, you two can go out in the morning for breakfast and bring Daddy some back. Try to be creative if you can't get him to sleep later. Good Luck, and I feel for your hubby, I don't sleep well either......so I know how frustrating it can be.