BA 719 then BA 352 at Heathrow
Zurich → London → Nice
Timetable, London time
18:25BA 719 from Zurich at the gate
18:05BA 352 to Nice leaves the gate
23 h 40 apart on the timetable, overnight
BA 352 leaves 23 h 40 after BA 719 arrives on the timetable: more than half a day, so not a connection we count.