BA 6 then BA 864 at Heathrow
Tokyo → London → Prague
Timetable, London time
19:20BA 6 from Tokyo at the gate
18:05BA 864 to Prague leaves the gate
22 h 45 apart on the timetable, overnight
BA 864 leaves 22 h 45 after BA 6 arrives on the timetable: more than half a day, so not a connection we count.