Jet Lag Engine

Jet Lag Engine turns a time-zone shift into one practical travel timeline. Enter your itinerary and usual sleep, then see what to do now, what comes next, and why each recommendation exists. The deterministic engine plans useful sleep opportunities, correctly timed light or low-light periods, and optional caffeine cutoffs before planned sleep. Built for real itineraries: • Search 7,884 airports by city or IATA code • Enter each departure and arrival in airport-local time • Add multiple ordered layovers • Choose gradual destination adjustment or staying nearer home time • Mark fixed intervals when sleep is impossible • Record recent sleep and wake times to adjust the estimate • Log coffee for cutoff feedback; melatonin remains record-only • Follow Now and a day-by-day timeline across time zones • Receive optional local notifications with quiet hours • Keep the current plan visible in small and medium widgets • Use a travel-window Live Activity during the journey • Keep trip history, duplicate plans, and export plan data • Works offline with no account, ads, analytics, or subscription Airport search, daylight feasibility, plan generation, notifications, widgets, and Live Activities work on the device. Your information leaves only when you explicitly share an export. Jet Lag Engine estimates body-clock timing from the sleep information you provide. It does not measure biological phase or guarantee alertness or recovery. Guidance is general and educational, not medical advice.