BA 6449 then UA 1 at San Francisco
Los Angeles → San Francisco → Singapore
Timetable, San Francisco time
23:27BA 6449 from Los Angeles at the gate
22:40UA 1 to Singapore leaves the gate
23 h 13 apart on the timetable, overnight
UA 1 leaves 23 h 13 after BA 6449 arrives on the timetable: more than half a day, so not a connection we count.