Zodiac Systems (Vedic versus Western)
The difference between the zodiac systems currently used in astrology can be confusing when one doesn't understand the reasons behind this discrepancy. The Sidereal Zodiac (also known as the Vedic Zodiac) is a fixed system. In spite of its name, it had originally nothing to do with Vedic culture or Vedic astrology. The Zodiac is the segment of the sky where one can observe the planets' movements.
Even though the constellations that lend their names to, and mark the signs of the zodiac are not the same size, a Zodiac sign is 30 degrees.
Each Sign/Rasi and consequently each House/Bhava is always 30 degrees.
The precession of the Equinoxes slowly “moves” the moment when the Sun is directly above the Equator “backwards”
The boundaries of the signs of the Zodiac are fixed. The precession of the equinoxes takes place slowly and without causing any confusion. The Spring Equinox occurs in the sign of Pisces in actuality.
The Tropical Zodiac (also known as the Western Zodiac) was not originally meant for astrological use. It was a calendar system best suited for higher latitudes where agricultural production depends on the seasons. In preindustrial times the beginning of spring was truly the most important "event" that needed to be correctly defined.
Keep in mind that equinoxes and solstices have nothing to do with the stars and planetary movements. These four yearly events are caused by the tilt in the axis of the Earth. During the times of the ancient Greek civilization the Spring Equinox occurred very close to "First Point of Aries". As in Western Culture almost every discipline tries to find its roots in Greek scientific and especially philosophical achievements, the beginning of spring (marked by the Spring Equinox) became so closely associated with the sign of Aries, that when the equinoxes preceded with time, people simply started counting the 30 degrees of Aries from the exact point where the Sun was at the moment of the equinox.
During Classical Antiquity the Spring Equinox occurred when the Sun was in the Cardinal Fire Sign Aries
If we go back farther in time, the Spring Equinox occurred in the sign of Taurus, making the bull the most potent symbol of fertility and renewal. Especially in the Fertile Crescent, one of the major cradles of civilization on the Northern Hemisphere, agriculture developed during the "Era of Taurus' which is attested by many archeological finds where the bull has clear religious and cultural significance.
The Apis Bull is the testament of earlier times when the Equinox happened during the Sun’s yearly transit in the Fixed Earth Sign Taurus
Right now the Equinox finds the Sun in the sign of Pisces. Even though the equinoxes are the most precise and correct markers of the changing of the seasons, their precession has nothing to do with the signs of the Zodiac (as they are completely unrelated to planetary movements).
Because of this "misuse" of a calendar, today we can encounter the "Western Zodiac" or the Tropical Zodiac. (The word "tropical" is coming from the Greek "tropos" meaning "turning around", referring to the Sun's "turning back" twice a year when it reaches the two Tropics.)
Only in the “Tropics” can the Sun ever be directly overhead.
Incidentally in our current era, when the Sun reaches the Tropic of Cancer, it is actually in the sign of Gemini, and when it reaches the Tropic of Capricorn it is in the sign of Sagittarius. (Further pointing to the discrepancy between the "actual Zodiac" and the "Western Zodiac".)
The discrepancy is 24 degrees (out of the 30 degrees of a sign/rasi) which is a very significant margin of error.
In reality the Sun only enters the Sign of Leo on August 17 ( 25 days later than “Western Astrology” claims!!!)
Professional Western Astrologers don't use the "Western Zodiac" (You cannot actually charge people money if your calculations are 24 degrees off!) In the contemporary parlance of Western Astrology the "actual Zodiac" is referred to as Sidereal Zodiac.