UA 124 then A3 780 at Athens
Newark → Athens → Zagreb
Timetable, Athens time
10:05UA 124 from Newark at the gate
07:35A3 780 to Zagreb leaves the gate
21 h 30 apart on the timetable, overnight
A3 780 leaves 21 h 30 after UA 124 arrives on the timetable: more than half a day, so not a connection we count.