BA 873 then BA 544 at Heathrow
Krakow → London → Bologna
Timetable, London time
18:05BA 873 from Krakow at the gate
13:55BA 544 to Bologna leaves the gate
19 h 50 apart on the timetable, overnight
BA 544 leaves 19 h 50 after BA 873 arrives on the timetable: more than half a day, so not a connection we count.