BA 855 then BA 988 at Heathrow
Prague → London → Berlin
Timetable, London time
16:15BA 855 from Prague at the gate
15:55BA 988 to Berlin leaves the gate
23 h 40 apart on the timetable, overnight
BA 988 leaves 23 h 40 after BA 855 arrives on the timetable: more than half a day, so not a connection we count.