A3 781 then LX 1839 at Athens
Zagreb → Athens → Zurich
Timetable, Athens time
18:00A3 781 from Zagreb at the gate
17:40LX 1839 to Zurich leaves the gate
23 h 40 apart on the timetable, overnight
LX 1839 leaves 23 h 40 after A3 781 arrives on the timetable: more than half a day, so not a connection we count.