Experts from the University of Texas Health Science Center at Houston recommend ideally two weeks before school starts to gradually move your child back from a summer schedule to a school schedule.
For instance, if your teen generally sleeps in until noon, have them arise at 11:45 to start, and each day wake them up earlier and earlier.
Also, limit computer and TV use at night. The light from both affects the biological clock, which could make them stay up later.
Finally, experts remind us that teens need more sleep, and you're fighting human nature by making them get up early.