AA 3996 then AA 1594 at Phoenix
Tucson → Phoenix → Austin
Timetable, Phoenix time
15:46AA 3996 from Tucson at the gate
13:58AA 1594 to Austin leaves the gate
22 h 12 apart on the timetable, overnight
AA 1594 leaves 22 h 12 after AA 3996 arrives on the timetable: more than half a day, so not a connection we count.