F9 1407 then DL 836 at Atlanta
Buffalo → Atlanta → Phoenix
Timetable, Atlanta time
16:26F9 1407 from Buffalo at the gate
16:25DL 836 to Phoenix leaves the gate
23 h 59 apart on the timetable, overnight
DL 836 leaves 23 h 59 after F9 1407 arrives on the timetable: more than half a day, so not a connection we count.