Seasons start and end on the equinoxes and the solstices. Winter begins on the winter solstice and ends on the spring equinox.
It also depends on which hemisphere you are in, the northern or the southern.
-- In the northern hemisphere, winter includes part of December, then January, February and part of March. The winter months are traditionally December, January, and February.
-- In the southern hemisphere, winter includes part of June, then July, August, and part of September. The winter months are traditionally June, July, and August.
I think it is about 5 hours.
From New York City to Los Angeles it is 2,776 mi (about 1 day 17 hours). Try Google Maps for other locations.
7 hours 46 minutes