QR 5515 then EW 2521 at Barcelona
Porto → Barcelona → Stuttgart
Timetable, Barcelona time
11:30QR 5515 from Porto at the gate
09:20EW 2521 to Stuttgart leaves the gate
21 h 50 apart on the timetable, overnight
EW 2521 leaves 21 h 50 after QR 5515 arrives on the timetable: more than half a day, so not a connection we count.