UA 3236 then DL 1891 at Houston
Mc Allen → Houston → Detroit
Timetable, Houston time
20:10UA 3236 from Mc Allen at the gate
15:32DL 1891 to Detroit leaves the gate
19 h 22 apart on the timetable, overnight
DL 1891 leaves 19 h 22 after UA 3236 arrives on the timetable: more than half a day, so not a connection we count.