FR 4546 then QR 3639 at Barcelona
Porto → Barcelona → Firenze
Timetable, Barcelona time
16:40FR 4546 from Porto at the gate
10:30QR 3639 to Firenze leaves the gatealso IB 5370, LL 5370, VY 6070
17 h 50 apart on the timetable, overnight
QR 3639 leaves 17 h 50 after FR 4546 arrives on the timetable: more than half a day, so not a connection we count.