FR 44 then OS 639 at Vienna
Athens → Vienna → Budapest
Timetable, Vienna time
07:25FR 44 from Athens at the gate
21:05OS 639 to Budapest leaves the gate
13 h 40 apart on the timetable
OS 639 leaves 13 h 40 after FR 44 arrives on the timetable: more than half a day, so not a connection we count.