UA 16 then BA 338 at Heathrow
Newark → London → Nice
Timetable, London time
06:20UA 16 from Newark at the gate
06:00BA 338 to Nice leaves the gate
23 h 40 apart on the timetable, overnight
BA 338 leaves 23 h 40 after UA 16 arrives on the timetable: more than half a day, so not a connection we count.