BA 339 then AA 137 at Heathrow
Nice → London → Los Angeles
Timetable, London time
12:15BA 339 from Nice at the gate
11:55AA 137 to Los Angeles leaves the gate
23 h 40 apart on the timetable, overnight
AA 137 leaves 23 h 40 after BA 339 arrives on the timetable: more than half a day, so not a connection we count.