There seems to be some sort of bug related to scheduled time of gate departure for many Southwest flights. After a flight actually departs the gate, the STD changes from whatever it was (i.e. the correct time) to match the ATD.
Here is an example of one of these instances. SWA1864 PHL-ATL today 7/23/20:
According to FA, the Gate Departure was Scheduled for 06:26AM EDT, and it actually departed at 06:26AM EDT. But if I had taken the same screen shot before the flight actually departed, it had shown the correct Scheduled 06:30AM EDT.
This is made clear when you look at the Southwest website for the flight status. It correctly shows that the flight was scheduled for 06:30 AM, and actually departed at 06:26 AM.
It does not happen for all Southwest flights, but quite a few. I’d say about 75%. And I haven’t noticed it for any other airlines at this time.
This is, of course, also reflected in the XML data feeds. In my use case of the data, I need to track if flights are departing on time, late, or early. This data has led to the erroneous conclusion that almost all of Southwest’s flights are departing exactly at D0, which is incorrect.
Has anyone else noticed this? Does anyone know what is causing it? And most importantly, hopefully it can be fixed.