KL 1532 then U2 2520 at Schiphol
Valencia → Amsterdam → London Luton
Timetable, Amsterdam time
19:35KL 1532 from Valencia at the gate
17:35U2 2520 to London Luton leaves the gate
22 h apart on the timetable, overnight
U2 2520 leaves 22 h after KL 1532 arrives on the timetable: more than half a day, so not a connection we count.