Tell us about your trip
Add your flights and your usual sleep pattern. That’s all the Circadian Model needs to map where your body clock is — and where it needs to be.
The shortest way through jetlag.
The Jetlag Fix builds a personal jetlag plan around your trip and your body clock — powered by our Circadian Model. Know exactly when to seek light, avoid it, and sleep, so your body catches up days sooner.
Free to download · Plans for any route
How it works01 02 03
Three steps to a shorter jetlag.
Get your personal plan
The model charts the fastest safe path between time zones and turns it into a simple day-by-day schedule, starting before you even fly.
Follow the moments that matter
Clear, well-timed guidance on when to seek light, avoid it, and sleep. A few right moves each day — no spreadsheets, no guesswork.
Following your plan
Three types of advice. That's it.
Every plan is a sequence of simple, well-timed instructions — the same three you'll meet in the app. When one comes up, here's all you need to do.
Seek Light
When the app tells you to Seek Light:
- Try to get as much light as you can.
- Going outside is ideal.
- When you can’t get sunlight, use bright artificial lights or increase screen brightness.
- Light therapy glasses can be a useful tool to easily get bright light.
Avoid Light
When the app tells you to Avoid Light:
- Try to avoid bright light as much as possible.
- Close any blinds and avoid sunlight especially.
- Decrease screen brightness when using devices.
- If you can’t control the light around you, use sunglasses or blue-blocking glasses.
Sleep
When the app tells you to try to Sleep:
- Get some sleep if you can.
- If you can’t sleep or it isn’t practical, just try to avoid light as much as possible.
- An eyemask or sunglasses can be great tools for this.
The science
Built on our Circadian Model.
Jetlag isn’t tiredness — it’s your internal clock running on the wrong time zone. Light is the strongest signal that moves it, and the timing of that light decides whether you shift forward, backward, or not at all.
Our in-house Circadian Model estimates the state of your body clock from your sleep history and travel schedule, then computes when light, darkness, and sleep will shift it fastest toward your destination. The result is a plan tuned to your body — not a generic list of travel tips.
- Models your clock, not an average traveler’s
- Times light and dark to the minute that moves you most
- Adapts day by day as your rhythm shifts
The Pain Score
Know how much a trip will hurt — before you fly.
Not every route hits your body the same way. The Circadian Model scores any trip's circadian impact out of 100 — your Pain Score — from the time zones crossed, the direction you fly, and how your flights land against your body clock.
Then it shows you what the plan is worth: the same trip, scored with and without your plan. That's days of jetlag you don't have to suffer through.
Features
Everything you need. Nothing that keeps you awake.
Personal, not generic
Every plan is computed from your sleep pattern, your route, and your dates. No two travelers get the same schedule.
Starts before you fly
Pre-shift in the days before departure so you land with most of the work already done.
Gentle by design
A dark, quiet interface that never blasts you with light — especially when the plan says avoid it.
Well-timed nudges
Notifications arrive at the moments that matter: seek light, avoid light, sleep window.
Any route, either direction
East or west, one leg or five — the model handles multi-stop trips and awkward layovers.
Works offline
Your full plan is on your phone. Airplane mode won’t take it away.
Inside the app
Calm on the surface. A model underneath.
FAQ
Good questions.
Most plans begin two to three days before departure — that’s where the easy wins are. But the model will still build a useful plan if you open the app the day you fly, or even after you land.
Your next trip starts on time.
Download The Jetlag Fix and let the Circadian Model do the maths.