KL 9864 then KL 1653 at Schiphol
Brussels → Amsterdam → Firenze
Timetable, Amsterdam time
13:32KL 9864 from Brussels at the gate
10:25KL 1653 to Firenze leaves the gate
20 h 53 apart on the timetable, overnight
KL 1653 leaves 20 h 53 after KL 9864 arrives on the timetable: more than half a day, so not a connection we count.