BA 581 then BA 746 at Heathrow
Milan → London → Geneva
Timetable, London time
14:35BA 581 from Milan at the gate
10:30BA 746 to Geneva leaves the gate
19 h 55 apart on the timetable, overnight
BA 746 leaves 19 h 55 after BA 581 arrives on the timetable: more than half a day, so not a connection we count.