UA 3919 then UA 2181 at Houston
Raleigh-Durham → Houston → New York LaGuardia
Timetable, Houston time
23:15UA 3919 from Raleigh-Durham at the gate
12:07UA 2181 to New York LaGuardia leaves the gate
12 h 52 apart on the timetable, overnight
UA 2181 leaves 12 h 52 after UA 3919 arrives on the timetable: more than half a day, so not a connection we count.