BA 461 then BA 746 at Heathrow
Madrid → London → Geneva
Timetable, London time
15:25BA 461 from Madrid at the gate
10:30BA 746 to Geneva leaves the gate
19 h 05 apart on the timetable, overnight
BA 746 leaves 19 h 05 after BA 461 arrives on the timetable: more than half a day, so not a connection we count.