Dating a pisces aries cusp
This included magical uses of the zodiac, as found, e.g., in the Sefer Raziel Ha Malakh.
(detailed view) The zodiacal signs are distinct from the constellations associated with them, not only because of their drifting apart due to the precession of equinoxes but also because the physical constellations take up varying widths of the ecliptic, so the Sun is not in each constellation for the same amount of time.
Such connections were taken up by Thomas Mann, who in his novel Joseph and His Brothers attributes characteristics of a sign of the zodiac to each tribe in his rendition of the Blessing of Jacob.
Babylonia or Chaldea in the Hellenistic world came to be so identified with astrology that "Chaldean wisdom" became among Greeks and Romans the synonym of divination through the planets and stars.
The thirteenth was left out: Ophiuchus, the bottom part of which interjects between Scorpio and Sagittarius.
Occasionally this difference between the astronomical constellations and the astrological signs is mistakenly reported in the popular press as a "change" to the list of traditional signs by some astronomical body like the IAU, NASA, or the Royal Astronomical Society.