This is really interresting but never helped me. I found a book about waking cycles https://en.wikipedia.org/wiki/Circadian_rhythm and even read more into scientific papers who where recently released (becouse of better measurement devices) https://en.wikipedia.org/wiki/Chronobiology . The newews discoveries broke the plain day-wake-cycle even into more periods over a day. They found out every human has a slighly different form of those cylces. This graph will propably give you an