Biological clocks are embedded in every aspect of human biology, guiding us toward the prime times of day to sleep, eat, think, and work. Award-winning scientist Russell Foster brings decades of study to this journey through the circadian rhythms that dominate our days and nights. He shows how the realities of 24/7 life—including night-shift work, overbooked calendars, and caring for newborns—disrupt the body clock, taking a toll on sleep and on mental and physical health. By dismantling long-standing myths and citing cutting-edge science, Foster empowers readers to get back into rhythm and live healthier, sharper lives: scheduling meals to prevent obesity and diabetes; timing medications to increase their effectiveness; getting better sleep through exposure to natural light; and much more. “If you want to embrace life,” Foster writes, “then embracing biological time will help you do this.