I am more than half way through the book "Why we sleep?" by Matthew Walker and it is not a surprise to me that misalignment of circadian rhythm with class schedules results in poor grades. The book goes into great detail on the importance of getting eight hours of sleep on a regular schedule. Getting less than eight hours of sleep is tied to every imaginable disease and poor memory. I highly recommend reading the book.

https://www.amazon.com/Why-We-Sleep-Unlocking-Dreams/dp/1501...