The Rite of Spring

The Spring Equinox:
There are two days each year when the daytime and nighttime hours are approximately equal -- each being 12 hours long. One occurs between March 19 and 21 and is called the Spring or Vernal Equinox. The other happens in September. These dates have strong ties to religious celebrations, both ancient and modern.

Modern astronomy aside, people have recognized the vernal equinox for thousands of years. There is no shortage of rituals and traditions surrounding the coming of spring. Many early peoples celebrated for the basic reason that their food supplies would soon be restored. The date is significant in Christianity because Easter always falls on the first Sunday after the first full moon after the vernal equinox. It is also probably no coincidence that 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 Nawruz, the Persian New Year. The celebration lasts 13 days and is rooted in the 3,000-year-old tradition of Zorastrianism. It is also the New year for the baha'is.





http://www.infoplease.com/spot/riteofspring1.html





Naw-Ruz is the first day of the new year. It coincides with the spring equinox in the northern hemisphere, which usually occurs on 21 March. Baha'u'llah explains that this feast day is to be celebrated on whatever day the sun passes into the constellation of Aries (i.e. the vernal equinox), even should this occur one minute before sunset (Q and A 35). Hence Naw-Ruz could fall on 20, 21, or 22 March, depending on the time of the equinox. ...





http://reference.bahai.org/search?max=10&lang=en&first=1&query=equinox