Jet Lag Engine — Support — 🤓 vandalen.dev

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To diagnose a problem, include the app and iOS versions, iPhone model, route, travel dates, algorithm and configuration versions, displayed event timezone, what you expected, and what happened. A plan export can help, but share it only if you are comfortable disclosing its itinerary and sleep-schedule contents.

Do not include passport details, booking references, payment information, precise medical information, or anything else the app does not need.

A trip or timeline looks wrong

Open Trip and verify every airport plus its local arrival and departure time. The app expects the time printed for each airport and stores the underlying instant with that airport’s IANA timezone, including DST and calendar-date changes.

Layovers must remain in travel order, and every arrival must follow the previous departure. If cabin service, work, boarding, or another known interval makes sleep impossible, add it under Fixed awake time and regenerate the plan.

Tap a timeline event to inspect its timezone, rationale, constraint status, and daylight feasibility. If the itinerary changed, use Adjust plan so the whole plan is regenerated coherently.

Actual sleep, coffee, and melatonin

Under Actual behavior, you can record up to five recent sleep and wake intervals. Their local timezones and midpoints update the app’s estimated sleep baseline when the plan is regenerated.

A coffee log can indicate that intake occurred after a planned cutoff. It does not estimate your personal caffeine metabolism or recommend a dose.

Melatonin remains record-only. It never changes recommendations, infers a phase shift, creates a reminder, or recommends an amount.

Notifications do not appear

Open Trip → Notification settings and enable the categories you want. Check whether iOS currently permits notifications for Jet Lag Engine. If permission was denied, open iPhone Settings and allow notifications for the app.

Quiet hours intentionally suppress noncritical local notifications. Adjusting or regenerating a plan removes that trip’s pending requests and schedules replacements.

Open Jet Lag Engine after installing or updating it so the active-plan snapshot can refresh. Add the small or medium widget from the iPhone widget gallery.

The Live Activity is available only between the trip’s first departure and final arrival. Confirm that Live Activities are enabled for Jet Lag Engine in iPhone Settings. iOS controls the exact refresh cadence of widgets and Live Activities; opening the app refreshes their shared snapshot.

Exporting, history, and deletion

The Trip tab lets you move the active plan to history, duplicate a previous trip, share a text summary or JSON plan export, delete history items, replace the active trip, or delete all app data.

Exports leave the app only after you choose a destination in the iOS share sheet. Deleting app data does not remove copies you previously exported.

Privacy and offline use

Jet Lag Engine has no account, advertising, analytics, tracking, custom backend, or third-party SDK. Airport search, timezone calculations, plan generation, daylight feasibility, local notifications, widgets, and the travel-window Live Activity work on the device.

Read the complete Jet Lag Engine privacy policy.

Safety

Jet Lag Engine estimates body-clock timing from the sleep information you provide. It offers general travel guidance, not medical advice, diagnosis, treatment, or an alertness guarantee.