BA 821 then BA 424 at Heathrow
Billund → London → Málaga
Timetable, London time
14:00BA 821 from Billund at the gate
13:50BA 424 to Málaga leaves the gate
23 h 50 apart on the timetable, overnight
BA 424 leaves 23 h 50 after BA 821 arrives on the timetable: more than half a day, so not a connection we count.