UA 6220 then DL 2709 at Houston
Savannah → Houston → Atlanta
Timetable, Houston time
08:43UA 6220 from Savannah at the gate
08:05DL 2709 to Atlanta leaves the gate
23 h 22 apart on the timetable, overnight
DL 2709 leaves 23 h 22 after UA 6220 arrives on the timetable: more than half a day, so not a connection we count.