BA 266 then BA 746 at Heathrow
Portland (Oregon) → London → Geneva
Timetable, London time
11:20BA 266 from Portland (Oregon) at the gate
10:30BA 746 to Geneva leaves the gate
23 h 10 apart on the timetable, overnight
BA 746 leaves 23 h 10 after BA 266 arrives on the timetable: more than half a day, so not a connection we count.