WN 259 then B6 8351 at Boston
St Louis → Boston → New York JFK
Timetable, Boston time
23:35WN 259 from St Louis at the gate
05:30B6 8351 to New York JFK leaves the gate
5 h 55 apart on the timetable, overnight
The last days
WN 259 and B6 8351 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.