UA 2131 then DL 836 at Atlanta
San Francisco → Atlanta → Phoenix
Timetable, Atlanta time
16:27UA 2131 from San Francisco at the gate
16:25DL 836 to Phoenix leaves the gate
23 h 58 apart on the timetable, overnight
DL 836 leaves 23 h 58 after UA 2131 arrives on the timetable: more than half a day, so not a connection we count.