RO 263 then GQ 671 at Istanbul
Bucharest → Istanbul → Athens
Timetable, Istanbul time
18:40RO 263 from Bucharest at the gate
10:30GQ 671 to Athens leaves the gate
15 h 50 apart on the timetable, overnight
GQ 671 leaves 15 h 50 after RO 263 arrives on the timetable: more than half a day, so not a connection we count.