UA 3441 then LN 744 at Dulles
Charlotte → Washington → Buffalo
Timetable, Washington time
11:55UA 3441 from Charlotte at the gate
04:00LN 744 to Buffalo leaves the gate
16 h 05 apart on the timetable, overnight
LN 744 leaves 16 h 05 after UA 3441 arrives on the timetable: more than half a day, so not a connection we count.