DL 1909 then DL 5850 at JFK
Salt Lake City → New York → Jacksonville
Timetable, New York time
05:00DL 1909 from Salt Lake City at the gate
08:50DL 5850 to Jacksonville leaves the gate
3 h 50 apart on the timetable
The last days
DL 1909 and DL 5850 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.