Keeping a routine is important for everyone, including children and adolescents, says pediatric sleep expert Reut Gruber, an associate professor in the department of psychiatry at McGill University. Your brain needs “zeitgebers” (time givers), or cues from the environment, to recognize day from night, she says. These zeitgebers include having breakfast and exposing yourself to daylight in the morning, for instance, Dr. Gruber says. At night, the body produces melatonin when it gets dark, which tells your brain it is time to go to sleep.