UA 3915 then UA 3921 at O'Hare
Miami → Chicago → Washington National
Timetable, Chicago time
22:25UA 3915 from Miami at the gate
22:00UA 3921 to Washington National leaves the gate
23 h 35 apart on the timetable, overnight
UA 3921 leaves 23 h 35 after UA 3915 arrives on the timetable: more than half a day, so not a connection we count.