How flight status works

Definitions

Scheduled time

The departure or arrival time in the airline’s timetable. Delays are measured from it.

Actual departure

For a US departure airport, the departure instant recorded by the FAA. Elsewhere, the time shown on the departure airport’s own board: some show take-off time, others the time the plane leaves the gate. The table below describes those boards, not FAA coverage.

Actual arrival

For a US destination, the arrival instant recorded by the FAA; missing FAA facts stay unknown, with no fallback to other sources. Elsewhere, the arrival airport’s own board is used where available, or other flight records for flight status. Other flight records do not replace a market’s fixed official settlement source.

Late

An arrival is late if it is more than 15 minutes after the scheduled arrival. 15 minutes or less counts as on time.

Cancelled

A flight the airline or airport reports as cancelled. Cancellations are counted separately, never as on time or late. For market settlement only, a flight that took off and returned to its departure airport also settles as cancelled, unless it flew again under the same flight number on a plan due to leave at least four hours before that number's next scheduled departure from the airport (at most a day after its own). Flight status and delay history don't count it as cancelled.

Diverted

A flight that landed somewhere other than its scheduled destination. It is left out of on-time and late counts.

Codeshares

One plane often flies under several airlines’ flight numbers. We count each flight once, however many numbers it is sold under.

Departure time by airport

US departure facts use FAA records only; missing FAA facts stay unknown. Elsewhere, airport boards report the departure times described below. Markets use their fixed official source and time basis, not a fallback record. A plane usually takes off a few minutes after leaving the gate, so a take-off time is later than a gate time.

Change log

1. October 8, 2026Added when a market settles a flight that returned to its departure airport as cancelled.
2. September 29, 2026Rebuilt the page: definitions, which departure time each airport reports, coverage counts, latency and this change log.
3. September 27, 2026New page layout. No definition changed.
4. September 26, 2026Revised the wording of the Chinese and Hindi versions.
5. September 16, 2026Added how a flight’s service date is chosen, and what the update time does and does not mean.
6. September 15, 2026Added the explainer on scheduled, estimated and actual times.
7. September 15, 2026First published: how flight status and delay history are worked out, including the 15-minute rule for late arrivals.