KL 1982 then KL 1017 at Schiphol
Belgrade → Amsterdam → London Heathrow
Timetable, Amsterdam time
08:35KL 1982 from Belgrade at the gate
20:40KL 1017 to London Heathrow leaves the gate
12 h 05 apart on the timetable
KL 1017 leaves 12 h 05 after KL 1982 arrives on the timetable: more than half a day, so not a connection we count.