OS 991 then DY 3580 at Copenhagen
Vienna → Copenhagen → Prague
Timetable, Copenhagen time
09:05OS 991 from Vienna at the gate
08:25DY 3580 to Prague leaves the gate
23 h 20 apart on the timetable, overnight
DY 3580 leaves 23 h 20 after OS 991 arrives on the timetable: more than half a day, so not a connection we count.