BA 961 then BA 344 at Heathrow
Hamburg → London → Nice
Timetable, London time
12:20BA 961 from Hamburg at the gate
11:45BA 344 to Nice leaves the gate
23 h 25 apart on the timetable, overnight
BA 344 leaves 23 h 25 after BA 961 arrives on the timetable: more than half a day, so not a connection we count.