BA 477 then BA 746 at Heathrow
Barcelona → London → Geneva
Timetable, London time
13:55BA 477 from Barcelona at the gate
10:30BA 746 to Geneva leaves the gate
20 h 35 apart on the timetable, overnight
BA 746 leaves 20 h 35 after BA 477 arrives on the timetable: more than half a day, so not a connection we count.