Here’s a link to all my posts in the Category of Astrology for ease of reference.

The following is an Article via Wikipedia

Western Astrology is the system of astrology most popular in Western countries. Western astrology is historically based on Ptolemy‘s Tetrabiblos (2nd century AD), which in turn was a continuation of Hellenistic and ultimately Babylonian traditions.

Western astrology is largely horoscopic, that is, it is a form of divination based on the construction of a horoscope for an exact moment, such as a person’s birth, in which various cosmic bodies are said to have an influence. Astrology in western popular culture is often reduced to sun sign astrology, which considers only the individual’s date of birth (i.e. the “position of the Sun” at that date).

Because astrology has failed in predictions when under scientific tests, it is generally regarded as pseudoscientific.

A central principle of astrology is integration within the cosmos. The individual, Earth, and its environment are viewed as a single organism, all parts of which are correlated with each other.^[1] Cycles of change that are observed in the heavens are therefore reflective (not causative) of similar cycles of change observed on earth and within the individual.^[2] This relationship is expressed in the Hermetic maxim “as above, so below; as below, so above”, which postulates symmetry between the individual as a microcosm and the celestial environment as a macrocosm.^[3] At the heart of astrology is the metaphysical principle that mathematical relationships express qualities or ‘tones’ of energy which manifest in numbers, visual angles, shapes and sounds – all connected within a pattern of proportion. Pythagoras first identified that the pitch of a musical note is in proportion to the length of the string that produces it, and that intervals between harmonious sound frequencies form simple numerical ratios.^[4] In a theory known as the Harmony of the Spheres, Pythagoras proposed that the Sun, Moon and planets all emit their own unique hum based on their orbital revolution,^[5] and that the quality of life on Earth reflects the tenor of celestial sounds which are physically imperceptible to the human ear.^[3] Subsequently, Plato described astronomy and music as “twinned” studies of sensual recognition: astronomy for the eyes, music for the ears, and both requiring knowledge of numerical proportions.^[6]

Later philosophers retained the close association between astronomy, optics, music and astrology, including Ptolemy, who wrote influential texts on all these topics.^[7] Al-Kindi, in the 9th century, developed Ptolemy’s ideas in De Aspectibus which explores many points of relevance to astrology and the use of planetary aspects.^[8]

The Zodiac

The zodiac is the belt or band of constellations through which the Sun, Moon, and planets move on their journey across the sky. Astrologers noted these constellations and so attached a particular significance to them. Over time they developed the system of twelve signs of the zodiac, based on twelve of the constellations through which the sun passes throughout the year, those constellations that are “Enlightened by the mind”. Most western astrologers use the tropical zodiac beginning with the sign of Aries at the Northern hemisphere Vernal Equinox always on or around March 21 of each year. The Western Zodiac is drawn based on the Earth’s relationship to fixed, designated positions in the sky, and the Earth’s seasons. The Sidereal Zodiac is drawn based on the Earth’s position in relation to the constellations, and follows their movements in the sky. Due to a phenomenon called precession of the equinoxes (where the Earth’s axis slowly rotates like a spinning top in a 25,700 year cycle), there is a slow shift in the correspondence between Earth’s seasons (and calendar) and the constellations of the zodiac. Thus, the tropical zodiac corresponds with the position of the earth in relation to fixed positions in the sky (Western Astrology), while the sidereal zodiac is drawn based on the position in relation to the constellations (sidereal zodiac).^[9]

The Twelve Signs

In modern Western astrology the signs of the zodiac are believed to represent twelve basic personality types or characteristic modes of expression. The twelve signs are divided into four elements fire, earth, air and water. Fire and air signs are considered masculine, while water and earth signs are considered feminine.^[10] The twelve signs are also divided into three qualities, Cardinal, fixed and mutable.^[11][12]

Sign			Approximate dates of Sun signs		Sun signs dates for current year 2015-2016		Element	Quality
			Start	End	Start	End
	Aries	The Ram	March 21	April 19	March 21	April 19	Fire	Cardinal
	Taurus	The Bull	April 20	May 20	April 20	May 20	Earth	Fixed
	Gemini	The Twins	May 21	June 21	May 21	June 21	Air	Mutable
	Cancer	The Crab	June 22	July 22	June 22	July 23	Water	Cardinal
	Leo	The Lion	July 23	August 22	July 24	August 27	Fire	Fixed
	Virgo	The Virgin	August 23	September 22	August 28	September 23	Earth	Mutable
	Libra	The Scales	September 23	October 23	September 24	October 23	Air	Cardinal
	Scorpio	The Scorpion	October 24	November 20	October 24	November 20	Water	Fixed
	Sagittarius	The Archer	November 21	December 22	November 21	December 22	Fire	Mutable
	Capricorn	The Sea Goat	December 23	January 20	December 23	January 17	Earth	Cardinal
	Aquarius	The Water Bearer	January 21	February 21	January 18	February 20	Air	Fixed
	Pisces	The Fish	February 22	March 20	February 21	March 20	Water	Mutable

• Note: these are only approximations and the exact date on which the sign of the sun changes varies from year to year.

Zodiac sign for an individual depends on the placement of planets and the ascendant in that sign. If a person has nothing placed in a particular sign, that sign will play no active role in their personality. On the other hand a person with, for example, both the sun and moon in Cancer, will strongly display the characteristics of that sign in their make up.