<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by exAC:
I don't think that the delay in display is new. I came to that conclusion a long time ago based on tracking via the web and tracking directly with the AC ops system. Trip.com also speaks of the display as "near real time".
I just checked AC124 which was due to leave YEG at 1700. It actually departed at 1708 [according to the AC web site]. Trip.com at 1709 said that it was scheduled to depart in 16 minutes.</font>
Maybe that is the actual queue time assigned by the ATC for that aircraft to take off. So that time is reserved as the departure time and shown on the flight tracker.