You are never in control of food, poop and sleep. Start by having a nightly ritual about the time he seems tired. Bathe, brush teeth, read two or three short stories then put him/her to bed. Adjust the time based on daylight, your needs, and how soon it is after a meal. Be consistent. Some children are loons and others larks; however, an eight year old should get 12-10 hours sleep. No naps during the day.
Wayne Yankus, MD, FAAP
expert panelist: pediatrics