You stand at the bathroom sink, yawn, and splash cold water on your face. You glance at the clock—it is 10 pm. Instead of putting on pajamas and crawling beneath the covers, you are dressing for work. You fill a thermos full of coffee and stumble out the door. On the drive to work, you rub your eyes and roll down the window a bit to keep from falling asleep at the wheel. You have trouble concentrating on your work and you struggle to stay awake through the night. Finally, it is quitting time and you can go home to bed. Just when you are about to drift off, a neighbor cranks up a lawn mower, the birds seem to chirp louder than usual, and you cannot ignore the sunlight seeping in around the corners of the drawn shades.

The lifestyle of a shift worker can be tough. The lack of sleep can lead to many problems, including depression, lower job productivity, health problems, and marital and family discord. It can also lead to accidents, both on the job and on the highway. The National Sleep Foundation (NSF) notes that shift workers are more likely to drive to or from work drowsy at least a few days a month than those who work a regular daytime schedule.

For millions of American shift workers the frustration of struggling to stay awake while they perform their jobs and then battling with insomnia and other sleep-related problems once they return home is too real. But if shift work creates so many problems, why not just stick with a daytime routine? Well, many people who make their living at odd hours provide crucial services, such as emergency care and police and fire protection. There is also a demand for round-the-clock workers in the transportation and manufacturing industries. Shift work is essential in our 24-hour society. Our bodies, however, are regulated by a different clock.