UA 3905 then UA 564 at Houston
Cancún → Houston → Calgary
Timetable, Houston time
13:29UA 3905 from Cancún at the gate
09:33UA 564 to Calgary leaves the gate
20 h 04 apart on the timetable, overnight
UA 564 leaves 20 h 04 after UA 3905 arrives on the timetable: more than half a day, so not a connection we count.