UA 1665 then DL 5807 at Boston
San Francisco → Boston → Charlotte
Timetable, Boston time
07:56UA 1665 from San Francisco at the gate
20:10DL 5807 to Charlotte leaves the gate
12 h 14 apart on the timetable
DL 5807 leaves 12 h 14 after UA 1665 arrives on the timetable: more than half a day, so not a connection we count.