UA 4019 then UA 3237 at Houston
Mc Allen → Houston → Mc Allen
Timetable, Houston time
06:26UA 4019 from Mc Allen at the gate
19:45UA 3237 to Mc Allen leaves the gate
13 h 19 apart on the timetable
UA 3237 leaves 13 h 19 after UA 4019 arrives on the timetable: more than half a day, so not a connection we count.