AA 2230 then UA 4573 at Houston
Miami → Houston → Huntsville
Timetable, Houston time
23:58AA 2230 from Miami at the gate
18:10UA 4573 to Huntsville leaves the gate
18 h 12 apart on the timetable, overnight
UA 4573 leaves 18 h 12 after AA 2230 arrives on the timetable: more than half a day, so not a connection we count.