The Constellations of the Zodiac
The ecliptic, or the position of the Sun as it’s perceived from
the revolving Earth, passes through the constellations that formed
the Zodiac - Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra,
Scorpio, Sagittarius, Capricorn, Aquarius and Pisces. Zodiac signs
were originally determined by which constellation the Sun was "in"
on the day you were born.
Early astronomers observed the Sun traveling through the signs
of the Zodiac in the course of one year, spending about a month in
each. Thus, they calculated that each constellation extends 30
degrees across the ecliptic.
TAURUS = MAY 14 - JUNE 19
CANCER = JULY 21 - AUG 9
PISCES = MARCH 12 - APRIL 18
http://photosophize.blogspot.com/2009/01/ophiuchus-13th-zodiac-sign.html