FR 3040 then FR 4597 at Barcelona
Prague → Barcelona → Porto
Timetable, Barcelona time
21:15FR 3040 from Prague at the gate
20:40FR 4597 to Porto leaves the gate
23 h 25 apart on the timetable, overnight
FR 4597 leaves 23 h 25 after FR 3040 arrives on the timetable: more than half a day, so not a connection we count.