VN 98 then SQ 1491 at San Francisco
Ho Chi Minh City → San Francisco → New York JFK
Timetable, San Francisco time
17:00VN 98 from Ho Chi Minh City at the gate
06:00SQ 1491 to New York JFK leaves the gate
13 h apart on the timetable, overnight
SQ 1491 leaves 13 h after VN 98 arrives on the timetable: more than half a day, so not a connection we count.