A3 961 then GQ 670 at Athens
Bucharest → Athens → Istanbul
Timetable, Athens time
11:50A3 961 from Bucharest at the gate
07:00GQ 670 to Istanbul leaves the gate
19 h 10 apart on the timetable, overnight
GQ 670 leaves 19 h 10 after A3 961 arrives on the timetable: more than half a day, so not a connection we count.