Timeshifter was featured on Condé Nast Traveler’s Bright Ideas in Travel 2026. Read the full list of winners here.
What traveler, in their tedious shuffle back to the cramped rear of the plane, hasn’t gazed longingly at the lie-flat seats in business and first class? Surely the jet lag wouldn’t hit so hard if you could recline all the way back and get some proper rest, right? But that assumes jet lag is a sleep deprivation problem when, in fact, it’s not.
“Everything that’s shared today publicly about how to address jet lag is wrong,” says Mickey Beyer-Clausen, co-founder and CEO of Timeshifter, a circadian tech company that aims to help travelers and shift workers adjust to new time zones and manage irregular schedules. “The biggest challenge is that circadian science is not publicly very well known.”
Timeshifter is working to change that.
Understanding circadian science begins with the fact that our each of our brains contain a tiny “clock,” a cluster of neurons called the suprachiasmatic nucleus, which is smaller than a grain of rice. This clock determines your body’s daily cycle of sleep and alertness—the circadian rhythm. “What we’re talking about is internal time,” explains Martha Merrow, a chronobiologist and visiting professor of circadian medicine at the University of Oxford. Everybody’s got their own internal time, which is unique to them, she says. Two people who share the same schedule can still have different internal times due to a range of factors, among them a person’s “chronotype,” which describes if you’re an early or late riser.
Whenever you fly through a few time zones, your internal time can disagree with the actual time in your destination. That disagreement is jet lag. Yet much of the conventional advice about jet lag doesn’t address the key mechanism that helps your internal clock adjust. In short: It’s all about light, with sleep only playing a supporting role.
“Sleep comes into it in two ways,” Merrow says. “One, if you don’t get enough of it, you really feel horrible. But the other way is that when you sleep, you actually are actively modifying your light environment by closing your eyes. So by sleeping at the ‘right time’ or ‘wrong time,’ you can help the phase shifting that you’re trying to achieve—or you can hinder it.” That exposure to light is “the main thing,” she says, that helps our internal rhythms adjust to wherever we are.
That’s why snoozing on a flight doesn’t always help; it might shift your circadian rhythm in the ‘wrong’ direction. “You can sleep for eight hours and feel massively jet-lagged because all your circadian clocks are out of whack,” according to Beyer-Clausen. The solution is getting the timing right for light exposure, darkness, and sleep. “You have to personalize that for each traveler,” he says.
That’s why the Timeshifter jet lag app asks for your age, your usual sleep times, your caffeine and melatonin habits, and your chronotype—early bird, night owl, or neither. Then you enter your flight numbers; the app pulls info about your departure and arrival times. With all that info, the app’s algorithm formulates a plan that begins days before you depart. It tells you when to expose yourself to light or avoid it; when to use and avoid caffeine; and when to snooze (and take melatonin, if you like).
