DL 1504 then UA 571 at Atlanta
Pittsburgh → Atlanta → San Francisco
Timetable, Atlanta time
07:54DL 1504 from Pittsburgh at the gate
07:00UA 571 to San Francisco leaves the gate
23 h 06 apart on the timetable, overnight
UA 571 leaves 23 h 06 after DL 1504 arrives on the timetable: more than half a day, so not a connection we count.