UA 799 then DL 2646 at O'Hare
Grand Cayman → Chicago → Boston
Timetable, Chicago time
18:13UA 799 from Grand Cayman at the gate
16:40DL 2646 to Boston leaves the gate
22 h 27 apart on the timetable, overnight
DL 2646 leaves 22 h 27 after UA 799 arrives on the timetable: more than half a day, so not a connection we count.