BA 873 then BA 822 at Heathrow
Krakow → London → Billund
Timetable, London time
18:05BA 873 from Krakow at the gate
16:05BA 822 to Billund leaves the gate
22 h apart on the timetable, overnight
BA 822 leaves 22 h after BA 873 arrives on the timetable: more than half a day, so not a connection we count.