UA 3600 then DM 5421 at O'Hare
Montréal → Chicago → Punta Cana
Timetable, Chicago time
08:00UA 3600 from Montréal at the gate
04:20DM 5421 to Punta Cana leaves the gate
20 h 20 apart on the timetable, overnight
DM 5421 leaves 20 h 20 after UA 3600 arrives on the timetable: more than half a day, so not a connection we count.