As one might expect from a book with a foreword by Dr. Oz, this is part science, part horoscope. I already had a pretty good idea of my chronotype from my wearable, and the info in this book roughly aligns with those data. I read some sections and skimmed the rest. The "best time to do x" chapters are the weakest and sometimes contradict information in other sections. Still, it does give me some things to consider about timing and energy.