In the summer of 2017, when communication professor Jeffery Gentry moved from Oklahoma to accept a position at Eastern New Mexico University, he was pleasantly surprised to find it easier to get up in the morning. The difference, he realized, was early morning light. On September mornings in Portales, New Mexico, Gentry rose with the sun at around 6:30 am, but at that time of day in Oklahoma, it was still dark.
As the Earth rotates, the sun reaches the eastern edge of a time zone first, with sunrise and sunset occurring progressively later as you move west. Gentry’s move had taken him from the western side of Central Time in Oklahoma to the eastern edge of Mountain Time. Following his curiosity into the scientific literature, he discovered the field of chronobiology, the study of biological rhythms, such as how cycles of daylight and dark affect living things. “I really just stumbled upon it from being a guinea pig in my own experiment,” he said.