A3 977 then EW 2685 at Athens
Belgrade → Athens → Stuttgart
Timetable, Athens time
19:00A3 977 from Belgrade at the gate
11:40EW 2685 to Stuttgart leaves the gate
16 h 40 apart on the timetable, overnight
EW 2685 leaves 16 h 40 after A3 977 arrives on the timetable: more than half a day, so not a connection we count.