I've been reading all the posts and am very curious as well because I'm going to start in April with my daughter who will be 1 and another baby around 1 as well,,,, Right now, my daughter doesn't have a fixed schedule but usually sleeps around the same times as your son (10-12) (3-4/5),,, I hear you because when a baby is tired, it's hard to focus on anything else, but I agree with the posts that say gradually change their sleep habits,, although I think the babies will also let you know when they're tired and when they've had enough sleep,,, good luck and keep posting- I'm learning lots as well!!