Equinox

The fall or autumnal equinox is approaching. At this point the length of the day equals the night for every location in the world. After this point the night will become longer than the day in the northern hemisphere and the opposite will occur in the southern hemisphere. Many cultures who are/were more in touch with the planet than we are regard this event as one of four important celebrations that mark the passage of the year. The others include the vernal equinox and the summer and winter solstices (the longests and shortest days of the year respectively, in the northern hemisphere).

Another important aspect of this time of year is that the sun rises exactly in the east and sets exactly in the west. Just in case you're lost in the woods right now.

The mayans created one of their temples in such a way that at the exact time of the equinox the shadow looks like a snake crawling down the steps. When it reaches the bottom the shawdow connects to a large serpent head.

So, the actually date of the equinox is Sept. 22, 2005, 6:23 P.M. EDT, but the conditions can be observed already and should last until Sept.25th. So get out there and celebrate.

Some Links:
Mayan Calendar Information (it's more exact than ours!)