IAU Definition Walter Berg Zodiac Signs (With OPHIUCHUS Added)
According to astrologists, Western tropical astrology has long been detached from the constellations eponymous of the signs, due to the axial precession of the equinoxes over the centuries since the introduction of the zodiac by the Chaldeans. By contrast, in sidereal astrology the astrological signs remain attached to the constellations, while the vernal equinox has moved away from Aries over time. Walter Berg breaks from historical tradition to combine sidereal astrology with the IAU's official constellation boundaries defined in 1930, creating a 13-sign system. This results in astrological signs that correspond directly to the time the Sun spends in their eponymous constellations. For example, the Sun spends forty-five days in Virgo and only six days in Scorpio. The 13th sign is Ophiuchus, where the Sun passes during the first two weeks of December.