UA 511 then BR 658 at O'Hare
Washington National → Chicago → Toronto Pearson
Timetable, Chicago time
14:27UA 511 from Washington National at the gate
11:30BR 658 to Toronto Pearson leaves the gate
21 h 03 apart on the timetable, overnight
BR 658 leaves 21 h 03 after UA 511 arrives on the timetable: more than half a day, so not a connection we count.