UA 3913 then UA 2135 at Houston
Denver → Houston → Fort Lauderdale
Timetable, Houston time
21:22UA 3913 from Denver at the gate
14:28UA 2135 to Fort Lauderdale leaves the gate
17 h 06 apart on the timetable, overnight
UA 2135 leaves 17 h 06 after UA 3913 arrives on the timetable: more than half a day, so not a connection we count.