KL 1009 then BA 858 at Heathrow
Amsterdam → London → Prague
Timetable, London time
14:25KL 1009 from Amsterdam at the gate
13:55BA 858 to Prague leaves the gate
23 h 30 apart on the timetable, overnight
BA 858 leaves 23 h 30 after KL 1009 arrives on the timetable: more than half a day, so not a connection we count.