UA 997 then UA 3757 at Dulles
Accra → Washington → Buffalo
Timetable, Washington time
04:55UA 997 from Accra at the gate
17:00UA 3757 to Buffalo leaves the gate
12 h 05 apart on the timetable
UA 3757 leaves 12 h 05 after UA 997 arrives on the timetable: more than half a day, so not a connection we count.