You did the flight. Now do the science.
A light, sleep and caffeine schedule built from your actual flights, cited to the study behind each number.
Seek bright light 06:00–08:00
Avoid caffeine after 14:00
A sample. Not your data — you haven't given us any yet.
Jet lag is not a character flaw. It's a phase shift.
Your body clock does not know you changed time zones. It finds out the hard way, at roughly a day per hour of shift, unless something moves it faster.
Light exposure, sleep timing and caffeine can move it — in the right order, at the right hour, in the right direction depending on whether you flew east or west. Get the order wrong and you can make the shift slower, not faster.
That is the part that does not fit on a napkin. Jet Laggard works it out per trip, from your actual outbound and return flights.
How it works
Enter your flights
Outbound and return. That's the whole form.
Get a schedule
Light, sleep and caffeine timing, modelled for that specific shift and direction.
Follow it
Or don't. It won't take it personally, and it will still be there tomorrow.
It is quietly serious science wearing a joke as a coat.
The schedule comes from a phase-response-curve model of how light shifts the circadian clock — the same class of model used in circadian research — tuned per trip to your outbound and return itinerary, not a fixed table by time-zone count.
The jokes are somewhere else in the app. They are never in the schedule.
Every number is shown with the study it came from — including the three the app admits are educated guesses rather than published findings.
It has opinions, in the right places
Dry, not chirpy. The instructions stay literal — that part is health-adjacent and gets no jokes. Everything around it does.
"No trips. Enviable, in a way."
"Consulting the sun."
"Adjusted. You may now be insufferable about it."
Web access, or Android news
The iPhone app is open to everyone on the App Store. The web version is by invitation, and the Android app is on its way. Choose one below and you'll hear back once, within a few days.
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