QR 3754 then LA 5752 at Barcelona
Santander → Barcelona → Catania
Timetable, Barcelona time
19:05QR 3754 from Santander at the gate
15:40LA 5752 to Catania leaves the gate
20 h 35 apart on the timetable, overnight
LA 5752 leaves 20 h 35 after QR 3754 arrives on the timetable: more than half a day, so not a connection we count.