FR 2508 then FR 6523 at Barcelona
Cologne → Barcelona → Bratislava
Timetable, Barcelona time
21:45FR 2508 from Cologne at the gate
21:15FR 6523 to Bratislava leaves the gate
23 h 30 apart on the timetable, overnight
FR 6523 leaves 23 h 30 after FR 2508 arrives on the timetable: more than half a day, so not a connection we count.