Monday, September 17, 2012

How is the start of autumn determined?

On the first day of autumn or the fall equinox, day and night are each about 12 hours long. Therefore the Fall Equinox or the start of autumn is when day when night and day are of equal length making the start of Autumn for September 22, more specifically in the Northern Hemisphere on September 22 at 10:49 A.M. EST.