FB 807 then LX 1839 at Athens
Sofia → Athens → Zurich
Timetable, Athens time
19:50FB 807 from Sofia at the gate
17:40LX 1839 to Zurich leaves the gate
21 h 50 apart on the timetable, overnight
LX 1839 leaves 21 h 50 after FB 807 arrives on the timetable: more than half a day, so not a connection we count.