Later school start times are associated with improved academic performance, as evidenced by a study in Edina, Minnesota, where SAT scores for the top 10% of students increased from 1288 to 1500 after the start time shifted from 7:25 AM to 8:30 AM.

“they shifted their school start times from 7:25 5 to 8:30 in the morning and then they wanted to ask what is the consequence of that on the academic performance of their students and the metric that they used in these teenagers that they were focusing on was something called the SAT score which is a score I had to learn when I first came to the United States is a critical assessment test that will largely determine which university you go to and they did an analysis which was clever they focused on the top 10% performing students which you could argue those are the ones that are closest to the ceiling performance and the hardest to expect any benefit from sleep so in the year before they made the time change the average score of those top 10% performing students was 1,288 which turns out to be a pretty good SAT score the following year after they made the time change the average score for that top 10% was 1,500”