DL 1581 then UA 6094 at Houston
Detroit → Houston → Denver
Timetable, Houston time
10:27DL 1581 from Detroit at the gate
14:11UA 6094 to Denver leaves the gate
3 h 44 apart on the timetable
The last days
DL 1581 and UA 6094 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.