BR 646 then UA 3683 at O'Hare
Anchorage → Chicago → Buffalo
Timetable, Chicago time
17:10BR 646 from Anchorage at the gate
14:17UA 3683 to Buffalo leaves the gate
21 h 07 apart on the timetable, overnight
UA 3683 leaves 21 h 07 after BR 646 arrives on the timetable: more than half a day, so not a connection we count.