A3 355 then GQ 670 at Athens
Santorini → Athens → Istanbul
Timetable, Athens time
12:10A3 355 from Santorini at the gate
06:55GQ 670 to Istanbul leaves the gate
18 h 45 apart on the timetable, overnight
GQ 670 leaves 18 h 45 after A3 355 arrives on the timetable: more than half a day, so not a connection we count.