UA 571 then DL 9960 at San Francisco
Atlanta → San Francisco → Seattle
Timetable, San Francisco time
11:24UA 571 from Atlanta at the gatealso VA 8403, NZ 9005
11:15DL 9960 to Seattle leaves the gate
23 h 51 apart on the timetable, overnight
DL 9960 leaves 23 h 51 after UA 571 arrives on the timetable: more than half a day, so not a connection we count.