UA 3511 then AA 1203 at Charlotte
Newark → Charlotte → Buffalo
Timetable, Charlotte time
09:43UA 3511 from Newark at the gate
08:55AA 1203 to Buffalo leaves the gate
23 h 12 apart on the timetable, overnight
AA 1203 leaves 23 h 12 after UA 3511 arrives on the timetable: more than half a day, so not a connection we count.