UA 4346 then UA 3907 at Houston
Brownsville → Houston → Washington
Timetable, Houston time
08:32UA 4346 from Brownsville at the gate
07:00UA 3907 to Washington leaves the gate
22 h 28 apart on the timetable, overnight
UA 3907 leaves 22 h 28 after UA 4346 arrives on the timetable: more than half a day, so not a connection we count.