UA 1535 then AA 1408 at DFW
Houston → Dallas-Fort Worth → Huatulco
Timetable, Dallas-Fort Worth time
19:35UA 1535 from Houston at the gate
10:49AA 1408 to Huatulco leaves the gate
15 h 14 apart on the timetable, overnight
AA 1408 leaves 15 h 14 after UA 1535 arrives on the timetable: more than half a day, so not a connection we count.