UA 796 then WN 791 at Boston
San Francisco → Boston → Nashville
Timetable, Boston time
06:06UA 796 from San Francisco at the gate
19:30WN 791 to Nashville leaves the gate
13 h 24 apart on the timetable
WN 791 leaves 13 h 24 after UA 796 arrives on the timetable: more than half a day, so not a connection we count.