LX 338 then BA 864 at Heathrow
Zurich → London → Prague
Timetable, London time
19:15LX 338 from Zurich at the gate
18:05BA 864 to Prague leaves the gate
22 h 50 apart on the timetable, overnight
BA 864 leaves 22 h 50 after LX 338 arrives on the timetable: more than half a day, so not a connection we count.