DL 539 then DL 955 at Atlanta
Portland (Oregon) → Atlanta → Las Vegas
Timetable, Atlanta time
19:27DL 539 from Portland (Oregon) at the gate
19:21DL 955 to Las Vegas leaves the gate
23 h 54 apart on the timetable, overnight
DL 955 leaves 23 h 54 after DL 539 arrives on the timetable: more than half a day, so not a connection we count.