UA 5501 then UA 3907 at Houston
Oklahoma City → Houston → Washington
Timetable, Houston time
11:01UA 5501 from Oklahoma City at the gate
07:00UA 3907 to Washington leaves the gate
19 h 59 apart on the timetable, overnight
UA 3907 leaves 19 h 59 after UA 5501 arrives on the timetable: more than half a day, so not a connection we count.