FR 3036 then FR 4587 at Barcelona
Krakow → Barcelona → Porto
Timetable, Barcelona time
10:30FR 3036 from Krakow at the gate
09:50FR 4587 to Porto leaves the gate
23 h 20 apart on the timetable, overnight
FR 4587 leaves 23 h 20 after FR 3036 arrives on the timetable: more than half a day, so not a connection we count.