What is the avertage bedtime for a 13 year old?

Now I have been working with children for over 15 years and one common problem in families is bedtimes. At the age of 13 your teenager is no longer a child and you need to give your teen responsibility. They should be able to set their own bedtime so long it is under 11:30pm. For the first week or so your teenager will probally take advantage of this and go to bed the latest possible time. But soon they will learn from their mistake and set themselves a sensible bedtime