EC 3651 then A3 4020 at Athens
Milan → Athens → Thessaloniki
Timetable, Athens time
23:00EC 3651 from Milan at the gate
18:30A3 4020 to Thessaloniki leaves the gate
19 h 30 apart on the timetable, overnight
A3 4020 leaves 19 h 30 after EC 3651 arrives on the timetable: more than half a day, so not a connection we count.