After a reasonably mild winter, Bozeman (and the rest of the Northern Hemisphere) will launch into Spring on March 20. Here are some basic facts about that magnificent day.

On March 20, 2015, at precisely 6:45 p.m. EDT, the sun will cross directly over the earth's equator. This moment is known as the vernal equinox in the Northern Hemisphere.

Because the sun is positioned above the equator, day and night are about equal in length all over the world during the equinoxes.

The date is significant in Christianity because Easter always falls on the first Sunday after the first full moon after the vernal equinox.

Early Egyptians built the Great Sphinx so that it points directly toward the rising sun on the day of the vernal equinox.

The first day of spring also marks the beginning of Nowruz, the Persian New Year. The celebration lasts 13 days and is rooted in the 3,000-year-old tradition of Zorastrianism.