EC 1703 then UX 7703 at Madrid
Nice → Madrid → Barcelona
Timetable, Madrid time
20:40EC 1703 from Nice at the gate
15:15UX 7703 to Barcelona leaves the gate
18 h 35 apart on the timetable, overnight
UX 7703 leaves 18 h 35 after EC 1703 arrives on the timetable: more than half a day, so not a connection we count.