BA 349 then BA 576 at Heathrow
Nice → London → Milan Linate
Timetable, London time
21:05BA 349 from Nice at the gate
18:35BA 576 to Milan Linate leaves the gate
21 h 30 apart on the timetable, overnight
BA 576 leaves 21 h 30 after BA 349 arrives on the timetable: more than half a day, so not a connection we count.