BA 503 then BA 746 at Heathrow
Lisbon → London → Geneva
Timetable, London time
14:00BA 503 from Lisbon at the gate
10:30BA 746 to Geneva leaves the gate
20 h 30 apart on the timetable, overnight
BA 746 leaves 20 h 30 after BA 503 arrives on the timetable: more than half a day, so not a connection we count.