EC 7154 then LA 5751 at Barcelona
Milan → Barcelona → Athens
Timetable, Barcelona time
17:15EC 7154 from Milan at the gate
17:10LA 5751 to Athens leaves the gate
23 h 55 apart on the timetable, overnight
LA 5751 leaves 23 h 55 after EC 7154 arrives on the timetable: more than half a day, so not a connection we count.