UA 2853 then DL 3876 at Denver
San Antonio → Denver → Austin
Timetable, Denver time
10:15UA 2853 from San Antonio at the gate
09:42DL 3876 to Austin leaves the gate
23 h 27 apart on the timetable, overnight
DL 3876 leaves 23 h 27 after UA 2853 arrives on the timetable: more than half a day, so not a connection we count.