I went to a large union high school for a while. Split classes. 2 different start times. I had to be on the bus at 6:00am. It wasn’t fun but it didn’t hurt me. It’s actually a good thing to discipline yourself to get up early.
One of my grandsons starts school at 7:15. His school has had those hours forever. I used to sub there and had to be at the school by 7. On the positive side, they get out at 2:15.