FR 3036 then UX 3644 at Barcelona
Krakow → Barcelona → Belgrade
Timetable, Barcelona time
23:40FR 3036 from Krakow at the gate
20:35UX 3644 to Belgrade leaves the gate
20 h 55 apart on the timetable, overnight
UX 3644 leaves 20 h 55 after FR 3036 arrives on the timetable: more than half a day, so not a connection we count.