DL 3879 then DL 2604 at Detroit
Cleveland → Detroit → New York LaGuardia
Timetable, Detroit time
11:23DL 3879 from Cleveland at the gate
17:58DL 2604 to New York LaGuardia leaves the gate
6 h 35 apart on the timetable
The last days
DL 3879 and DL 2604 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.