A new app could soon help you fight jet lag and reduce the fatigue of shift work by micromanaging your inner clock.

The innovation from the University of Michigan helps users adapt to new time zones and schedules by identifying biological “shortcuts” that can be accessed through controlled exposure to light and darkness. "Overcoming jet lag is fundamentally a math problem and we've calculated the optimal way of doing it," Dr. Danny Forger, a mathematician and developer of the app, said in a press release. "We're certainly not the first people to offer advice about this, but our predictions show the best and quickest ways to adjust across time zones."

The app — dubbed Entrain after “entrainment,” the scientific term for synchronizing circadian rhythm — relies on natural light as the strongest regulator of our inner clocks. When we travel through time zones or work through the night, our bodies fall out of touch with its natural light-darkness rhythm, which typically leads to insomnia and fatigue. Entrain helps you avoid these consequences by duping your body into thinking it is still on schedule.

An accompanying study published in the journal Public Library of Science Computational Biology shows how two primary mathematical models are used to divide the user’s day into “blocks” of exposure to light or darkness. Depending on your itinerary or schedule, the app will tell you when to seek out natural light and when you should remain in the dark.

If you’re prescribed “bright outdoor light” in the middle of the night, you can use indoor lights or a therapeutic light box. Similarly, if the app tells you to stay in the dark at noon, you can either remain indoors or wear sunglasses that block out blue wavelength light.

Curing Jet Lag

The app is by no means the first attempt to “cure” traveler’s insomnia and worker’s fatigue. Another example is a recent study from the University of Manchester, in which the authors show how a particular enzyme may be used to reset the body clock. Similarly, a 2013 study from the University of Notre Dame highlight genes that may be used to developed a “jet lag pill.”

According to Olivia Walch, the doctoral candidate who built the app, Entrain has a clear advantage over other entrainment methods, as it lets you reach targets around the circadian clock much faster. Image your inner clock as a regular wall clock: While most methods push you along its circumference, Entrain offers a shortcut.

"The way other approaches get these points to line up again is by inching along on the outside of the circle, sometimes pushing you towards and sometimes pulling you away from the target. But our schedules can just cut through the middle," she explained. "This is almost like a body hack to get yourself entrained faster."