FR 6596 then BA 483 at Barcelona
Manchester → Barcelona → London Heathrow
Timetable, Barcelona time
23:40FR 6596 from Manchester at the gate
15:30BA 483 to London Heathrow leaves the gate
15 h 50 apart on the timetable, overnight
BA 483 leaves 15 h 50 after FR 6596 arrives on the timetable: more than half a day, so not a connection we count.