DS5 on a good day / night sleeps about 9hrs (with help of Melatonin and Hydroxyzine). When he was younger before Melatonin started working on him, he was running on 4hrs of sleep / day. It was exhausting to say the least! DS3 either gets 7hrs in one stretch (usually from 2am - 9am), or sleeps in two long naps (8pm-midnight and 7am-11am) ... and from time to time dozes off in the car or doesn't sleep at all.