AA 642 then UA 2164 at O'Hare
Dallas-Fort Worth → Chicago → Phoenix
Timetable, Chicago time
13:10AA 642 from Dallas-Fort Worth at the gate
11:08UA 2164 to Phoenix leaves the gate
21 h 58 apart on the timetable, overnight
UA 2164 leaves 21 h 58 after AA 642 arrives on the timetable: more than half a day, so not a connection we count.