There are thirteen constellations in the
sky, not twelve. Western astrologers use twelve signs of
the Zodiac instead of thirteen, because in Western
astrology a sign,
and a constellation,
are not the same thing.
In Western astrology the position of the star, even of an
entire constellation is irrelevant. All that matters to
Western astrologers is the position of the Sun, Moon, and
planets along the ecliptic, that is, the longitude. Not even
the latitude of a celestial body matters, and is not even
looked at in most cases. It is almost as if the rest of
the heavens below and above the ecliptic plane were little
more than fancy background. The real Action Hero is the
ecliptic plane, and the astronomical background may have
value only when speaking of Astrological Ages.
What makes astrologers even more resistant to change,
however, is that most of the proponents clamouring for
change are professional astronomers who usually don't know
a thing about real astrology, and who often don't even
possess a healthy respect for practitioners of the art and
science of astrology. You can change someone if you have a
respect for them; it is quite a different matter changing
someone whom you don't respect, particularly if that
special someone has a healthy respect for him- or herself.
A Bucksfanian astrologer, however, cannot deny a basic
fact: there are at least 13 constellations traced by the
ecliptic, the 13th constellation being Ophiuchus, and the
constellation of Orion practically touches the ecliptic!
Actually things get even more complicated when we consider
the actual motion of the Sun through the constellations.
According to astronomical data I've seen, the Sun enters
the constellation of Orion between the 18th and 20th of
June; it enters the constellation of Sextans on the 3rd of
September; it enters Ophiuchus on the 29th of November;
and finally, it enters Cetus on the 27th of March. A
similar argument can be put forward for the Moon and the
planets as well.
The figure below puts the traditional astrological map of
the Zodiac in parallel with the ecliptic, and the
astronomical map of the Zodiac:


| Gates of Heaven + 2 |
|
| Astrological Age | Begins |
| Capricorn |
I Use |
| Aquarius |
I Know |
| Pisces | I Believe |
| Aries |
I Am |
| Taurus | I Have |
| Orion |
I Save |
| Gemini | I Think |
| Cancer | I Feel |
| Leo | I Will |
| Virgo | I Analyse |
| Libra |
I Balance |
| Scorpio | I Desire |
| Ophiuchus |
I Create |
| Sagittarius | I See |
I saw in the night visions, and behold, there came with the clouds of the sky one like a son of man, and he came even to the ancient of days, and they brought him near before him. There was given him dominion, and glory, and a kingdom, that all the peoples, nations, and languages should serve him: his dominion is an everlasting dominion, which shall not pass away, and his kingdom that which shall not be destroyed.
He showed me a river of water of life, clear as crystal, proceeding out of the throne of God and of the Lamb, in the middle of its street. On this side of the river and on that was the tree of life, bearing twelve kinds of fruits, yielding its fruit every month. The leaves of the tree were for the healing of the nations. There will be no curse any more. The throne of God and of the Lamb will be in it, and his servants serve him.