As my son was transitioning into a twin size bed, my husband and I were worried that he would get out of bed, in which he did too early in the morning. I looked online for any tools or tips to help keep him in bed. This is what I found, Teach Me Time Alarm Clock. My son is only 3 so he doesn't know how to tell time yet but the cool feature with this is that it changes colors.
He gets so excited that it turns green and proud that he stays in bed until then. There are options to have the clock speak the time, have an alarm go off as well, but that scared him so the colors work best for us. The nice thing is that if my son gets up after 6:15am the light will be green but it is not so intrusive as to wake him up if he feels like sleeping in.
Lastly, this timer will grow with him, as he gets older there are games and extra buttons to aid in his success. For a mom I give this product 5 STARS.