BA 965 then BA 722 at Heathrow
Hamburg → London → Zurich
Timetable, London time
21:30BA 965 from Hamburg at the gate
17:20BA 722 to Zurich leaves the gate
19 h 50 apart on the timetable, overnight
BA 722 leaves 19 h 50 after BA 965 arrives on the timetable: more than half a day, so not a connection we count.