UA 494 then AS 648 at Seattle
San Francisco → Seattle → Tucson
Timetable, Seattle time
09:40UA 494 from San Francisco at the gate
08:58AS 648 to Tucson leaves the gate
23 h 18 apart on the timetable, overnight
AS 648 leaves 23 h 18 after UA 494 arrives on the timetable: more than half a day, so not a connection we count.