UA 2453 then UA 3907 at Houston
Jacksonville → Houston → Washington
Timetable, Houston time
08:36UA 2453 from Jacksonville at the gate
07:00UA 3907 to Washington leaves the gate
22 h 24 apart on the timetable, overnight
UA 3907 leaves 22 h 24 after UA 2453 arrives on the timetable: more than half a day, so not a connection we count.