BA 965 then BA 862 at Heathrow
Hamburg → London → Prague
Timetable, London time
21:30BA 965 from Hamburg at the gate
17:40BA 862 to Prague leaves the gate
20 h 10 apart on the timetable, overnight
BA 862 leaves 20 h 10 after BA 965 arrives on the timetable: more than half a day, so not a connection we count.