A3 991 then FR 44 at Athens
Istanbul → Athens → Vienna
Timetable, Athens time
11:55A3 991 from Istanbul at the gate
06:00FR 44 to Vienna leaves the gate
18 h 05 apart on the timetable, overnight
FR 44 leaves 18 h 05 after A3 991 arrives on the timetable: more than half a day, so not a connection we count.