BA 634 then GQ 670 at Athens
London Heathrow → Athens → Istanbul
Timetable, Athens time
16:05BA 634 from London Heathrow at the gate
07:00GQ 670 to Istanbul leaves the gate
14 h 55 apart on the timetable, overnight
GQ 670 leaves 14 h 55 after BA 634 arrives on the timetable: more than half a day, so not a connection we count.