BA 893 then BA 750 at Heathrow
Sofia → London → Geneva
Timetable, London time
21:50BA 893 from Sofia at the gate
19:10BA 750 to Geneva leaves the gate
21 h 20 apart on the timetable, overnight
BA 750 leaves 21 h 20 after BA 893 arrives on the timetable: more than half a day, so not a connection we count.