BA 349 then BA 822 at Heathrow
Nice → London → Billund
Timetable, London time
21:05BA 349 from Nice at the gate
17:20BA 822 to Billund leaves the gate
20 h 15 apart on the timetable, overnight
BA 822 leaves 20 h 15 after BA 349 arrives on the timetable: more than half a day, so not a connection we count.