GQ 681 then A3 866 at Athens
Sofia → Athens → Prague
Timetable, Athens time
21:55GQ 681 from Sofia at the gate
17:15A3 866 to Prague leaves the gate
19 h 20 apart on the timetable, overnight
A3 866 leaves 19 h 20 after GQ 681 arrives on the timetable: more than half a day, so not a connection we count.