FR 6712 then JU 571 at Madrid
Budapest → Madrid → Belgrade
Timetable, Madrid time
18:10FR 6712 from Budapest at the gate
12:40JU 571 to Belgrade leaves the gate
18 h 30 apart on the timetable, overnight
JU 571 leaves 18 h 30 after FR 6712 arrives on the timetable: more than half a day, so not a connection we count.