BA 349 then BA 966 at Heathrow
Nice → London → Hamburg
Timetable, London time
21:05BA 349 from Nice at the gate
12:00BA 966 to Hamburg leaves the gate
14 h 55 apart on the timetable, overnight
BA 966 leaves 14 h 55 after BA 349 arrives on the timetable: more than half a day, so not a connection we count.