Teenagers and sleep have long puzzled parents, teachers, and scientists alike. One of the most widely discussed ideas in education today is whether schools should start later in the morning to align with adolescent sleep cycles. During puberty, biological rhythms shift—a phenomenon known as delayed sleep phase. This means teens naturally fall asleep later at night and need to wake later in the morning to get adequate rest. Yet most schools begin early, often before 8:00 a.m., forcing students to operate on schedules that clash with their internal clocks. Key concepts in this debate include circadian rhythm, academic performance, and mental health. Sleep research shows that insufficient rest can impair memory, focus, and emotional regulation. Advocates for later start times highlight studies where schools that shifted schedules reported better attendance, improved grades, and reduced rates of depression among students. On the other hand, practical concerns like transportation logistics, after-school activities, and parent work schedules complicate policy changes. Historically, early school start times became common during the industrial era, when schedules prioritized adult work shifts and transportation efficiency over adolescent biology. Today, medical organizations such as the American Academy of Pediatrics recommend later starts, but implementation varies widely. The core question is whether educational systems should adapt to teenage biology.