BA 349 then BA 762 at Heathrow
Nice → London → Basel
Timetable, London time
21:05BA 349 from Nice at the gate
17:30BA 762 to Basel leaves the gate
20 h 25 apart on the timetable, overnight
BA 762 leaves 20 h 25 after BA 349 arrives on the timetable: more than half a day, so not a connection we count.