St. Louis Public Schools presents plan to shift middle and high school start times to about 8:00 and 9:30 a.m.

St. Louis Public Schools officials outlined a proposal and research supporting later bell times for middle and high school students during an online community forum, saying the district is considering moving from a three-tier schedule to two tiers with start times near 8:00 a.m. and 9:30 a.m.

Hanley Chang, a social scientist at Mathematica and an SLPS parent who led the presentation, summarized the scientific rationale: “major medical associations, including, the American Academy of Pediatrics, recommend that middle and high schools start later. And by later, they mean 08:30AM or later,” he said, citing biological and empirical evidence linking later starts to more sleep and better outcomes.

The presentation included a prerecorded explanation from Eric Herzog, a biologist at Washington University, who described the brain’s circadian clock: “these 20,000 or so neurons are sort of the atomic clock in our brains,” Herzog said, explaining how…