UA 5209 then DL 2709 at Houston
Tucson → Houston → Atlanta
Timetable, Houston time
12:55UA 5209 from Tucson at the gate
08:05DL 2709 to Atlanta leaves the gate
19 h 10 apart on the timetable, overnight
DL 2709 leaves 19 h 10 after UA 5209 arrives on the timetable: more than half a day, so not a connection we count.