FR 1644 then OS 253 at Vienna
Rome → Vienna → Hamburg
Timetable, Vienna time
21:30FR 1644 from Rome at the gate
12:45OS 253 to Hamburg leaves the gate
15 h 15 apart on the timetable, overnight
OS 253 leaves 15 h 15 after FR 1644 arrives on the timetable: more than half a day, so not a connection we count.