UA 565 then UA 5646 at O'Hare
Washington → Chicago → Sioux Falls
Timetable, Chicago time
07:29UA 565 from Washington at the gate
19:45UA 5646 to Sioux Falls leaves the gate
12 h 16 apart on the timetable
UA 5646 leaves 12 h 16 after UA 565 arrives on the timetable: more than half a day, so not a connection we count.