FR 7538 then FR 4585 at Barcelona
Milan → Barcelona → Porto
Timetable, Barcelona time
08:05FR 7538 from Milan at the gate
06:00FR 4585 to Porto leaves the gate
21 h 55 apart on the timetable, overnight
FR 4585 leaves 21 h 55 after FR 7538 arrives on the timetable: more than half a day, so not a connection we count.