Sleep training is when you teach a child when to go to bed and what time they should wake up. The process puts the child on a set schedule with the hopes of them getting consistent 7-8 hours of sleep, or more, depending on their needs.  The clock itself is for children who still cannot tell time. Dr. Harris explains that instead of numbers, a sleep training clock uses light to signal that it is now morning and is time for the child to wake up. There are many options on the market, but sometimes simplicity is better.