Flight status monitoring is a scheduling problem as much as a data problem. Checking every followed flight every minute would waste provider quota. Checking every flight once a day would miss the changes people care about.
FlightDan uses an adaptive cadence based on where the flight is in its lifecycle.
Far ahead: confirm that the flight exists
Airlines do not publish every future occurrence at the same time. For a trip months away, FlightDan may only be able to find the nearest published schedule for that flight number.
In that case, FlightDan can show a clearly marked provisional schedule and check periodically for the exact dated occurrence. There is little value in checking every few minutes while publication is still months away.
Approaching departure: increase attention
As the operating date approaches, useful details begin to settle:
- The exact occurrence becomes available.
- Scheduled times may change.
- Terminals and gates may appear.
- Operational delays become possible.
FlightDan therefore checks progressively more often. On the day of travel, the interval shortens further.
Around departure: watch closely
Near departure and while a flight is active, a small status change can affect real plans. This is when FlightDan uses its shortest normal interval.
The exact information depends on the configured provider and airport coverage. A provider might report stages such as boarding, departed, en route, arrived, cancelled, or diverted.
After arrival: stay useful for greeters
After a flight lands, FlightDan keeps it live for 90 minutes and checks it at a slower cadence. This gives people meeting the flight a quick place to see late gate, terminal, baggage, or corrected arrival details without spending quota at the in-flight rate.
After that window, FlightDan marks the follow as complete and stops active monitoring. Cancelled and diverted flights complete immediately.
If a provider never reports a clean terminal status, FlightDan also uses the expected arrival window to avoid polling indefinitely.
How FlightDan establishes a baseline
When you follow a dated flight, FlightDan saves the current status with that tracked-flight record. The saved observation becomes the comparison baseline, so a real transition found on the next poll can produce an alert—even if the service restarted in between. The operating date also keeps repeated flight numbers on separate monitoring and notification paths.
If a flight has no previous observation at all, the first successful check establishes the baseline quietly. Later checks are compared with it, and FlightDan sends a message only when the reported status changes.