UA 3873 then AA 3354 at Houston
Kansas City → Houston → Phoenix
Timetable, Houston time
10:47UA 3873 from Kansas City at the gate
07:00AA 3354 to Phoenix leaves the gate
20 h 13 apart on the timetable, overnight
AA 3354 leaves 20 h 13 after UA 3873 arrives on the timetable: more than half a day, so not a connection we count.