UA 2184 then DL 8841 at Dulles
Los Angeles → Washington → Toronto Pearson
Timetable, Washington time
00:40UA 2184 from Los Angeles at the gate
16:00DL 8841 to Toronto Pearson leaves the gate
15 h 20 apart on the timetable
DL 8841 leaves 15 h 20 after UA 2184 arrives on the timetable: more than half a day, so not a connection we count.