EC 3749 then IB 5170 at Barcelona
Milan → Barcelona → Bilbao
Timetable, Barcelona time
21:30EC 3749 from Milan at the gate
14:40IB 5170 to Bilbao leaves the gate
17 h 10 apart on the timetable, overnight
IB 5170 leaves 17 h 10 after EC 3749 arrives on the timetable: more than half a day, so not a connection we count.