FB 851 then KL 1008 at Heathrow
Sofia → London → Amsterdam
Timetable, London time
16:45FB 851 from Sofia at the gate
14:05KL 1008 to Amsterdam leaves the gate
21 h 20 apart on the timetable, overnight
KL 1008 leaves 21 h 20 after FB 851 arrives on the timetable: more than half a day, so not a connection we count.