Vernal equinox From Wikipedia, the free encyclopediaThe vernal equinox (or spring equinox) marks the beginning of astronomical spring. It occurs during the month of March in the Northern Hemisphere, and during September in the Southern Hemisphere. In Chinese culture the vernal equinox marks the middle of spring. At the same moment that the vernal equinox occurs in one hemisphere, it is the time of the autumnal equinox in the other hemisphere.
In 2006, the Northern Hemisphere's vernal equinox falls on March 20 at 18:26 UTC.
In Indiana's Mounds State Park
there are earthwork structures that seem to have been constructed
with astronomical observation elements.
The structures have been dated at 160 B.C.E.
One such work, the so-called "Circle Mound" is aligned exactly east-west.
Actually an oblong,
if you stand at the east end at sundown
you will see it sites the sundown down the middle
in spring equinox.
Spring equinox is 13:26 (1: 26 PM) EST on Monday, 20 March 2006.
Sundown Monday is 18:54 (6:54 PM) EST.
Enjoy.