UA 1970 then UA 8172 at San Francisco
Cleveland → San Francisco → Boston
Timetable, San Francisco time
21:45UA 1970 from Cleveland at the gatealso VA 8489, NZ 9046, OZ 9526
12:45UA 8172 to Boston leaves the gate
15 h apart on the timetable, overnight
UA 8172 leaves 15 h after UA 1970 arrives on the timetable: more than half a day, so not a connection we count.