KL 1003 then BA 632 at Heathrow
Amsterdam → London → Athens
Timetable, London time
09:00KL 1003 from Amsterdam at the gate
08:15BA 632 to Athens leaves the gate
23 h 15 apart on the timetable, overnight
BA 632 leaves 23 h 15 after KL 1003 arrives on the timetable: more than half a day, so not a connection we count.