Where your scheduled, published trips starts (or ends) sometimes has no bearing on where you actually go to start working, or where your trip ends.
For example: Had a trip starting near PHL, operating to Oslo. instead I was airlined to HSV and operated out of HSV. Another trip was airline to HSV to DH to Europe, to start operating in Europe. Instead I was airlined to FAR, to operate out of FAR.
Trip was scheduled to end in JFK. Instead it ended in MEL. Had others end in TPE, Kuwait, London, Riga, Paraguay, etc., etc.