Originally Posted by Ken hAAmer
OK, now I know something's up.
Yesterday I put my mom on a flight home, that I observed depart late. I also spoke to her last evening, and she confirmed the plane left several minutes late. (We're using the "door closed" as the departure time, so it's not a matter of door or jetway or pushback of takeoff.) It wasn't particularly late, only a few minutes, nothing to be concerned about. It just came up in the conversation of how the flight went.
But checking AC's Status function on their web page indicates the flight departed 4 minutes early. Now I know this to be untrue.
Another lesson learned from US carriers?
The actual departure time of the aircraft that is recorded in AC's system and therefore used to pay pilots and FA is once the pilots release the brakes. At the same time they will turn on "anti-collision" light on top of the aircraft indicating the aircraft is ready to push back. Next step is to call apron for push back and if it is busy they will make you wait few minutes, sometimes even more if there is an aircraft stuck behind you that is waiting for a gate...When I worked as a gate agent I never waited for push back. Once you see the light on you leave the gate area as that aircraft is considered departed.