AA 1999 then AA 1594 at Phoenix
Boston → Phoenix → Austin
Timetable, Phoenix time
19:49AA 1999 from Boston at the gate
13:58AA 1594 to Austin leaves the gate
18 h 09 apart on the timetable, overnight
AA 1594 leaves 18 h 09 after AA 1999 arrives on the timetable: more than half a day, so not a connection we count.