In our quest to live healthier, happier, and more productive lives, we often overlook a powerful tool within us: our internal clocks. The human body is genetically designed to coordinate the “when” of almost all 21 of life – sleep, work, even having fun. And we’re born differently. People with certain types of genes prefer morning activity, 22 those with other types prefer activity later on. Historically, those differences allowed humans to divide 23 by what they were best suited to. But that is no longer true in an age when artificial light and long-distance travel allow us to 24 ourselves from solar days and nights. Today the timing of our daily events often violates our natural rhythms. This can be annoying and 25 . Research has shown a connection between disordered biological times and serious diseases including cancer.