UA 418 then LN 744 at Dulles
Los Angeles → Washington → Buffalo
Timetable, Washington time
07:12UA 418 from Los Angeles at the gate
04:00LN 744 to Buffalo leaves the gate
20 h 48 apart on the timetable, overnight
LN 744 leaves 20 h 48 after UA 418 arrives on the timetable: more than half a day, so not a connection we count.