UA 595 then DL 3876 at Denver
Fort Myers → Denver → Austin
Timetable, Denver time
10:22UA 595 from Fort Myers at the gate
09:42DL 3876 to Austin leaves the gate
23 h 20 apart on the timetable, overnight
DL 3876 leaves 23 h 20 after UA 595 arrives on the timetable: more than half a day, so not a connection we count.