FR 6920 then BA 839 at Dublin
Barcelona → Dublin → London Heathrow
Timetable, Dublin time
23:55FR 6920 from Barcelona at the gate
20:40BA 839 to London Heathrow leaves the gate
20 h 45 apart on the timetable, overnight
BA 839 leaves 20 h 45 after FR 6920 arrives on the timetable: more than half a day, so not a connection we count.