KM 514 then OS 823 at Vienna
Valletta → Vienna → Thessaloniki
Timetable, Vienna time
19:45KM 514 from Valletta at the gate
12:30OS 823 to Thessaloniki leaves the gate
16 h 45 apart on the timetable, overnight
OS 823 leaves 16 h 45 after KM 514 arrives on the timetable: more than half a day, so not a connection we count.