DL 554 then DL 1588 at Atlanta
Seattle → Atlanta → Miami
Timetable, Atlanta time
19:53DL 554 from Seattle at the gate
18:59DL 1588 to Miami leaves the gate
23 h 06 apart on the timetable, overnight
DL 1588 leaves 23 h 06 after DL 554 arrives on the timetable: more than half a day, so not a connection we count.