India, Sept. 19 -- If you have ever wondered why astrology pays so much attention to the changing seasons, the answer starts with four important points in the year: the spring equinox, summer solstice, fall equinox and winter solstice.

These events are not the same, although they are often mentioned together. In astronomy, they mark different positions of Earth and the Sun. In Western astrology, they also mark important transitions in the zodiac calendar.

The Old Farmer's Almanac describes these four events as the turning points of the seasonal year. Each one is connected with one of the four cardinal zodiac signs: Aries, Cancer, Libra and Capricorn.

Astronomically, an equinox happens when the Sun crosses the celestial equator. There a...