Guides
How jet lag works, what moves the body clock, and how Jetlag Away turns a flight into a schedule. Each guide explains the mechanism and cites the research behind it. For a particular flight, jet lag by route shows the plan the app builds for it.
The body clock
Why it does not reset when you land, which way it has to move, and the hour that decides how light affects it.
How jet lag works, and how long it lasts
Why the body clock does not reset on arrival, what actually moves it, and how long the adjustment takes.
The core body temperature minimum: the hour that decides which way light moves you
What the temperature minimum is, how it is estimated from your usual sleep, and why it sits at the centre of every light instruction in a jet lag plan.
Why flying east is harder than flying west
The same number of time zones costs more going east than west, for a reason built into the body clock itself.
The long way round: why a big eastward trip can mean going to bed later
For an eastward shift of ten hours or more, moving the body clock later round the day can be as quick as moving it earlier, and it goes with the clock rather than against it.
Light, sleep and caffeine
The three things a plan times, and what each one does.
Light timing: when to seek it and when to avoid it
Light is the strongest signal your body clock listens to — and the same light helps or hurts depending only on when you get it.
Caffeine and jet lag: when to stop, and why the cutoff moves with your plan
Caffeine stays in the body for hours, so the last cup matters more than the first. How a jet lag plan times it against the sleep it is protecting.
Napping after a long-haul flight: how long, how late, and when not to
A short, early nap on arrival day can be a fair trade. A long or late one spends the night you need. How a jet lag plan decides whether to offer one at all.
Jet lag without melatonin: what light, sleep and caffeine timing can do
Light is the strongest signal the body clock takes, and it needs no prescription. What a plan built only on light, sleep and caffeine timing does, and where melatonin fits.
Planning a trip
How a flight becomes a schedule, when a short trip is not worth adjusting for, and what happens when the trip goes off-plan.
How Jetlag Away builds a plan
The inputs, the shift calculation, and what the day-by-day schedule actually asks of you.
Short trips and jet lag: when staying on home time beats adjusting
On a trip of two or three days, adjusting to local time can leave you halfway there when you fly home. Why a plan may keep your body clock at home instead, and what that costs.
When the plan meets the trip: how check-ins re-pace a jet lag schedule
A printed jet lag schedule assumes you followed it. A short daily check-in lets the remaining days adjust to what actually happened, without rewriting the nights already past.
Choosing an app
What to check before you pay, and what Jetlag Away keeps about you.
Choosing a jet lag app: what to check before you pay
Twelve questions that separate a jet lag plan from a list of tips, including where Jetlag Away fits and where it does not.
What a jet lag app needs to know about you, and where Jetlag Away keeps it
A jet lag plan needs your flight and your sleep hours, not your name or your location. What Jetlag Away stores, where, what stays on your phone, and what works offline.