Jet Lag Engine

Arrive on local time

Only for iPhone

Free · Designed for iPhone. Not verified for macOS.

iPhone

Turn an itinerary and sleep schedule into a private timeline for light, sleep, and caffeine—before, during, and after a time-zone shift. 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.

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The developer, Dennis Van Dalen, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

    Privacy practices may vary, for example, based on the features you use or your age. Learn More

    Accessibility

    The developer has not yet indicated which accessibility features this app supports. Learn More

    Information

    Seller
    • Dennis Van Dalen
    Size
    • 4.1 MB
    Category
    • Travel
    Compatibility
    Requires iOS 17.0 or later.
    • iPhone
      Requires iOS 17.0 or later.
    • Mac
      Requires macOS 14.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    • English and Dutch
    Age Rating
    9+
    Copyright
    • © 2026 Dennis van Dalen
  • Privacy Policy

    • More by Dennis Van Dalen

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