EK 6107 then SQ 1550 at San Francisco
Houston → San Francisco → Boston
Timetable, San Francisco time
10:46EK 6107 from Houston at the gatealso CA 7372
10:44SQ 1550 to Boston leaves the gate
23 h 58 apart on the timetable, overnight
SQ 1550 leaves 23 h 58 after EK 6107 arrives on the timetable: more than half a day, so not a connection we count.