The departure time is when the aircraft pushes back, or leaves the gate. The arrival time is when the aircraft arrives at the gate.
The times are recorded, and transmitted to the company automatically via our ACARS datalink. The 'off' time is sent when the park brake is released after all doors are closed. The 'on' time is recorded when the park brake is set after arrival at the gate. It is not sent until the first door is opened, but the actual time recorded is the 'park brake' time.
We have no control over this, as it is done automatically, so we cannot 'cheat' and give an on schedule time when we are late.
Airclues