UA 4648 then DL 1697 at Phoenix
Lagos → Phoenix → Boston
Timetable, Phoenix time
18:56UA 4648 from Lagos at the gate
14:20DL 1697 to Boston leaves the gate
19 h 24 apart on the timetable, overnight
DL 1697 leaves 19 h 24 after UA 4648 arrives on the timetable: more than half a day, so not a connection we count.