FR 9481 then OS 623 at Vienna
Cologne → Vienna → Dubrovnik
Timetable, Vienna time
13:25FR 9481 from Cologne at the gate
11:00OS 623 to Dubrovnik leaves the gate
21 h 35 apart on the timetable, overnight
OS 623 leaves 21 h 35 after FR 9481 arrives on the timetable: more than half a day, so not a connection we count.