A new law in California mandates that middle schools can’t start before 8 am, and high schools 8:30. This is based on years of studies showing kids need more sleep than they’re getting, teens in particular. But it remains to be seen whether a statewide ban on early classes will result in a generation of well-rested superkids or just push everyone’s bedtime a bit later. I produced this episode of Vox’s daily news podcast Today, Explained, which you can listen to here or on Apple Podcasts.