UA 3558 then WN 301 at Philadelphia
Washington → Philadelphia → Denver
Timetable, Philadelphia time
23:31UA 3558 from Washington at the gate
05:20WN 301 to Denver leaves the gate
5 h 49 apart on the timetable, overnight
The last days
UA 3558 and WN 301 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.