BA 8451 then KL 1671 at Schiphol
London City → Amsterdam → Catania
Timetable, Amsterdam time
11:35BA 8451 from London City at the gate
09:00KL 1671 to Catania leaves the gate
21 h 25 apart on the timetable, overnight
KL 1671 leaves 21 h 25 after BA 8451 arrives on the timetable: more than half a day, so not a connection we count.