Children’s sleep duration matters and it is in our power to change it. This is 1 of 2 cut-through findings of the systematic review and meta-analysis by Magee et al1 of interventions in this issue of JAMA Pediatrics, spanning 45 randomized clinical trials and nearly 14 000 children and adolescents aged 1 to 18 years. Specifically, sleep can be lengthened by around half an hour each night simply by encouraging earlier bedtimes.