FR 3040 then BA 487 at Barcelona
Prague → Barcelona → London Heathrow
Timetable, Barcelona time
22:40FR 3040 from Prague at the gate
19:20BA 487 to London Heathrow leaves the gate
20 h 40 apart on the timetable, overnight
BA 487 leaves 20 h 40 after FR 3040 arrives on the timetable: more than half a day, so not a connection we count.