F9 1116 then DL 726 at Atlanta
Las Vegas → Atlanta → Boston
Timetable, Atlanta time
17:31F9 1116 from Las Vegas at the gate
13:50DL 726 to Boston leaves the gate
20 h 19 apart on the timetable, overnight
DL 726 leaves 20 h 19 after F9 1116 arrives on the timetable: more than half a day, so not a connection we count.