WN 591 then UA 1610 at Denver
Baltimore → Denver → Tucson
Timetable, Denver time
10:15WN 591 from Baltimore at the gate
13:45UA 1610 to Tucson leaves the gate
3 h 30 apart on the timetable
The last days
WN 591 and UA 1610 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.