FR 6874 then FR 126 at Dublin
Barcelona → Dublin → London Gatwick
Timetable, Dublin time
21:40FR 6874 from Barcelona at the gate
19:20FR 126 to London Gatwick leaves the gate
21 h 40 apart on the timetable, overnight
FR 126 leaves 21 h 40 after FR 6874 arrives on the timetable: more than half a day, so not a connection we count.