UA 1388 then AA 6238 at DFW
Houston → Dallas-Fort Worth → Amarillo
Timetable, Dallas-Fort Worth time
16:05UA 1388 from Houston at the gate
08:25AA 6238 to Amarillo leaves the gate
16 h 20 apart on the timetable, overnight
AA 6238 leaves 16 h 20 after UA 1388 arrives on the timetable: more than half a day, so not a connection we count.