UA 3915 then UA 2813 at O'Hare
Miami → Chicago → Houston
Timetable, Chicago time
22:25UA 3915 from Miami at the gate
19:55UA 2813 to Houston leaves the gate
21 h 30 apart on the timetable, overnight
UA 2813 leaves 21 h 30 after UA 3915 arrives on the timetable: more than half a day, so not a connection we count.