UA 755 then DL 635 at San Francisco
Reno → San Francisco → Atlanta
Timetable, San Francisco time
09:28UA 755 from Reno at the gatealso AC 4415, NH 7379
21:42DL 635 to Atlanta leaves the gate
12 h 14 apart on the timetable
DL 635 leaves 12 h 14 after UA 755 arrives on the timetable: more than half a day, so not a connection we count.