FR 573 then KL 1504 at Madrid
Porto → Madrid → Amsterdam
Timetable, Madrid time
13:30FR 573 from Porto at the gate
13:05KL 1504 to Amsterdam leaves the gatealso SK 6743
23 h 35 apart on the timetable, overnight
KL 1504 leaves 23 h 35 after FR 573 arrives on the timetable: more than half a day, so not a connection we count.