OS 824 then OS 377 at Vienna
Thessaloniki → Vienna → Nice
Timetable, Vienna time
16:50OS 824 from Thessaloniki at the gate
12:35OS 377 to Nice leaves the gate
19 h 45 apart on the timetable, overnight
OS 377 leaves 19 h 45 after OS 824 arrives on the timetable: more than half a day, so not a connection we count.