FR 6921 then BA 487 at Barcelona
Dublin → Barcelona → London Heathrow
Timetable, Barcelona time
19:20FR 6921 from Dublin at the gate
18:20BA 487 to London Heathrow leaves the gate
23 h apart on the timetable, overnight
BA 487 leaves 23 h after FR 6921 arrives on the timetable: more than half a day, so not a connection we count.