TK 1855 then QR 3503 at Barcelona
Istanbul → Barcelona → Santander
Timetable, Barcelona time
17:05TK 1855 from Istanbul at the gate
11:20QR 3503 to Santander leaves the gate
18 h 15 apart on the timetable, overnight
QR 3503 leaves 18 h 15 after TK 1855 arrives on the timetable: more than half a day, so not a connection we count.