DL 8858 then QY 821 at Madrid
Atlanta → Madrid → Porto
Timetable, Madrid time
07:35DL 8858 from Atlanta at the gate
17:37QY 821 to Porto leaves the gate
10 h 02 apart on the timetable
The last days
DL 8858 and QY 821 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.