U2 2323 then FR 8003 at Barcelona
London Luton → Barcelona → Porto
Timetable, Barcelona time
20:10U2 2323 from London Luton at the gate
11:40FR 8003 to Porto leaves the gate
15 h 30 apart on the timetable, overnight
FR 8003 leaves 15 h 30 after U2 2323 arrives on the timetable: more than half a day, so not a connection we count.