Jet lag calculator
Say you are on the 18:30 out of Washington DC, landing in Paris at 08:00. Six time zones east, overnight, and something the next morning you need to be ready for.
Search "jet lag calculator" and you will find tools that take those two time zones and hand you a schedule. Sleep then. Wake then. Maybe melatonin.
It looks like an answer. It is not one. Your origin and destination time zones, plus a departure time, are not enough to tell anyone how to reduce jet lag based on real science. And wrong advice does not simply help less. It can push your body clock furhter away from the new time zone, making jet lag worse.
Why jet lag calculators fall short
The jet lag calculators on the market differ in how they look, not in what they know. Each one builds its schedule from time zones and clock times alone, which is why they all stop short in the same three places.
They do not:
- account for chronotype, sleep duration or in-flight behavior
- time light exposure and light avoidance correctly – the most critical factor in reducing jet lag
- support complex itineraries: return trips, multi-leg journeys, short layovers
Because they are not dynamic apps, they also cannot:
- send push notifications when time-critical advice needs to be followed
- update the schedule when a flight is delayed, canceled or rebooked
The result is generic guidance, hard to follow in real travel conditions and ineffective at meaningfully reducing jet lag.
What an app does that a calculator cannot
The Timeshifter jet lag app is dynamic. It knows where you are in the plan, and it changes when your trip changes.
Timeshifter's jet lag app is the most downloaded and highest-rated jet lag app in the world. Get personalized jet lag plans based on your sleep pattern, chronotype, itinerary, and personal preferences.
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Timeshifter:
- tells you when to act, not just what to do. Push notifications arrive at the moment each piece of advice matters: when to seek light, when to avoid it, when to take melatonin, when to stop caffeine. A static schedule cannot do this, and time-critical advice followed at the wrong hour does nothing.
- adapts when your flight does. Delays, cancellations and rebookings change the entire plan. It recognizes when you are flying, lets you edit flights in real time, and recalculates around the trip you are actually on rather than the one you booked.
- handles real itineraries. Return trips. Unlimited multi-leg journeys. Unlimited stopovers. Quick Turnarounds™ for trips too short to adapt to. A calculator handles one leg, one direction, once.
- is built around you, not just the time zones. Chronotype, your usual sleep timing and sleep duration, whether you use melatonin, whether you use caffeine. The Practicality Filter™ removes advice you could not realistically follow on that trip.
- uses every lever, and times each one. Timed light exposure and timed light avoidance. Melatonin timed both for circadian resetting and for sleep. Caffeine timed for alertness. Prophylactic naps, and naps substituted for sleep on early-morning flights. Most tools address one or two of these. Timed light avoidance – one of the most critical factors – is missing from almost all of them.
- gets better with use. Post-trip jet lag rating and compliance feedback, and settings you can change between trips.
