BA 865 then LX 339 at Heathrow
Prague → London → Zurich
Timetable, London time
08:00BA 865 from Prague at the gate
20:05LX 339 to Zurich leaves the gate
12 h 05 apart on the timetable
LX 339 leaves 12 h 05 after BA 865 arrives on the timetable: more than half a day, so not a connection we count.