BA 349 then LH 917 at Heathrow
Nice → London → Frankfurt am Main
Timetable, London time
21:05BA 349 from Nice at the gate
18:30LH 917 to Frankfurt am Main leaves the gate
21 h 25 apart on the timetable, overnight
LH 917 leaves 21 h 25 after BA 349 arrives on the timetable: more than half a day, so not a connection we count.