During the outbreak of the COVID-19 pandemic in 2020, high schools closed or transitioned to remote teaching.

The “natural experiment” caused by the abrupt shutdown of schools due to the COVID-19 pandemic led to a 2-h shift in the sleep of typically developing adolescents, longer sleep duration, improved sleep quality, and less daytime sleepiness compared to those experienced under the regular school-time schedule. In addition, participants reported decreased daytime sleepiness and increased daytime alertness consistent with extended and improved sleep. This suggests that the improved sleep could translate into improved daytime performance if later start times could be implemented through the school year.