UA 3902 then AC 502 at O'Hare
Rio De Janeiro → Chicago → Toronto Pearson
Timetable, Chicago time
17:01UA 3902 from Rio De Janeiro at the gate
10:15AC 502 to Toronto Pearson leaves the gate
17 h 14 apart on the timetable, overnight
AC 502 leaves 17 h 14 after UA 3902 arrives on the timetable: more than half a day, so not a connection we count.