F9 3227 then DL 3876 at Denver
Houston → Denver → Austin
Timetable, Denver time
12:20F9 3227 from Houston at the gate
09:42DL 3876 to Austin leaves the gate
21 h 22 apart on the timetable, overnight
DL 3876 leaves 21 h 22 after F9 3227 arrives on the timetable: more than half a day, so not a connection we count.