BA 873 then BA 924 at Heathrow
Krakow → London → Hannover
Timetable, London time
18:05BA 873 from Krakow at the gate
13:15BA 924 to Hannover leaves the gate
19 h 10 apart on the timetable, overnight
BA 924 leaves 19 h 10 after BA 873 arrives on the timetable: more than half a day, so not a connection we count.