http://en.wikipedia.org/wiki/Astrological_age#The_Age_of_Aquarius_.28The_Aquarian_age.29 [emphasis mine]:
Timeframes In 1928, at the Conference of the International Astronomical Union (IAU) in Leiden, the Netherlands, the edges of the 88 official constellations became defined in astronomical terms. The edge established between Pisces and Aquarius locates the beginning of the Aquarian Age around the year 2600.
The Austrian astronomer, Professor Hermann Haupt , [32] examined the question of when the Age of Aquarius begins in an article published in 1992 by the Austrian Academy of Science: with the German title "Der Beginn des Wassermannzeitalters, eine astronomische Frage?" ("The Start of the Aquarian Age, an Astronomical Question?"). Based on the boundaries accepted by IAU in 1928, Haupt's article investigates the start of the Age of Aquarius by calculating the entry of the spring equinox point over the parallel cycle (d = - 4°) between the constellations Pisces and Aquarius and reaches, using the usual formula of precession (Gliese, 1982), the year 2595. However Haupt concludes:
- "Though it cannot be expected that astrologers will follow the official boundaries of the constellations, there will be an attempt to calculate the entry of the spring equinox point into the constellation of Aquarius." ...
- "As briefly has been shown, the results and methods of astrology in many areas, such as concerning the Aquarian age, are controversial on their own and cannot be called scientific because of the many esoteric elements." [33]
- Zodiacal 30 degrees:
- Neil Mann interpretation: begins AD 2150.
- Dane Rudhyar's interpretation states that the Age of Aquarius will begin in AD 2062.
- Nicholas Campion in The Book of World Horoscopes indicates that he has collected over 90 dates provided by researchers for the start of the Age of Aquarius and these dates have a range of over 2,000 years commencing in the 15th century AD. [34] The range of dates for the possible start of the Aquarian age range from 1447 to 3621.
- Constellation boundary year:
- Shephard Simpson interpretation: begins in ca. AD 2680.
- Hermann Haupt interpretation begins in ca. AD 2595.
- Michael Sidi interpretation begins in ca. AD 2720.