A3 504 then A3 993 at Istanbul
Thessaloniki → Istanbul → Athens
Timetable, Istanbul time
16:55A3 504 from Thessaloniki at the gate
16:45A3 993 to Athens leaves the gate
23 h 50 apart on the timetable, overnight
A3 993 leaves 23 h 50 after A3 504 arrives on the timetable: more than half a day, so not a connection we count.