SQ 1543 then B6 378 at San Francisco
New York JFK → San Francisco → Fort Lauderdale
Timetable, San Francisco time
13:40SQ 1543 from New York JFK at the gate
11:30B6 378 to Fort Lauderdale leaves the gatealso SQ 1546, AD 7751
21 h 50 apart on the timetable, overnight
B6 378 leaves 21 h 50 after SQ 1543 arrives on the timetable: more than half a day, so not a connection we count.