DL 5641 then UA 2400 at Boston
Cleveland → Boston → San Francisco
Timetable, Boston time
19:35DL 5641 from Cleveland at the gate
18:01UA 2400 to San Francisco leaves the gate
22 h 26 apart on the timetable, overnight
UA 2400 leaves 22 h 26 after DL 5641 arrives on the timetable: more than half a day, so not a connection we count.