TK 817 then GQ 671 at Istanbul
Amman → Istanbul → Athens
Timetable, Istanbul time
13:50TK 817 from Amman at the gate
10:30GQ 671 to Athens leaves the gate
20 h 40 apart on the timetable, overnight
GQ 671 leaves 20 h 40 after TK 817 arrives on the timetable: more than half a day, so not a connection we count.