AA 2303 then AA 1594 at Phoenix
St Louis → Phoenix → Austin
Timetable, Phoenix time
16:48AA 2303 from St Louis at the gate
13:58AA 1594 to Austin leaves the gate
21 h 10 apart on the timetable, overnight
AA 1594 leaves 21 h 10 after AA 2303 arrives on the timetable: more than half a day, so not a connection we count.