FR 879 then BA 487 at Barcelona
Venezia → Barcelona → London Heathrow
Timetable, Barcelona time
21:10FR 879 from Venezia at the gate
19:20BA 487 to London Heathrow leaves the gate
22 h 10 apart on the timetable, overnight
BA 487 leaves 22 h 10 after FR 879 arrives on the timetable: more than half a day, so not a connection we count.