How to properly detect the expected departure time and arrival time of a flight that has been delayed?
It depends on if you’re using FlightXML2 or FlightXML3. With FlightXML3 there is an estimated_departure_time and estimated_arrival_time. You can compare that with filed_departure_time and filed_arrival_time to determine how delayed it is.
For FlightXML2, we only publish an esimatedarrivaltime. So for the delayed flight if you want an estimateddeparturetime you can subtract the filed_ete from the estimatedarrivaltime to get an approximation of that.