Let us look at this problem anew, and take advantage of the online resources which have become available in the last quarter century.
The astrological signs in your typical horoscope column are based on ecliptic longitude, with the vernal equinox set as zero. The first one-twelfth of the ecliptic after the equinox is Aries, the next one-twelfth is Taurus, and so on.
This is worthless for determining an “age” during which the vernal equinox resides in a given sign. You can’t measure the movement of the equinox with a coordinate system that moves with the equinox. Rather, you need a system of sidereal-ecliptic longitude, wherein the signs are matched to the actual constellations, not the equinox.
The problem, as elucidated by Mr. Jim Klann in his reply to Cecil, is that there is no perfect way to match the signs to the constellations. The signs are equal width, but neither the astronomical constellations (as defined by the International Astronomical Union) nor the traditional star asterisms which serve as the basis of the constellations have equal width.
What to do? Fortunately Mr. John Pratt has done a great deal of scut work on this topic, and evaluated a large number of sign-to-constellation matching algorithms based on metrics including goodness of fit, centering, and visible star placement. I don’t know Mr. John Pratt, but he seems to be a very anal and thorough person. If he isn’t a Doper, he should be. (Assuming that he is still alive; he produced his web site in 2001.)
Mr. Pratt concludes (see “5. The Solution”) that sign boundaries offset anywhere between 27.10 degrees and 29.38 degrees from the epoch-2000 equinox-ecliptic boundaries would be a viable match to the constellations. He settles on 27.56 degrees as the optimal offset, for reasons he discusses at length.
From here the math to determine our ages is simple. In the equations below, 25,772 represents the time for the vernal equinox to make a complete circuit of the ecliptic. The length of each age = (25,772 / 12) = 2,148 years; this is the length of time the equinox spends in each sign. This is a slight over-simplification because the equinox does not precess at a uniform rate, but it is close to uniform and we will live with this error.
Pratt’s minimum offset = 27.10 degrees. (27.10/360) * 25,772 = 1,940
Age of Pisces begins = 2,000 – 1,940 = A.D. 60
Age of Pisces ends and Aquarius begins = 60 + 2,148 = A.D. 2208
Pratt’s optimal offset = 27.56 degrees. (27.56/360) * 25,772 = 1,973
Age of Pisces begins = 2,000 – 1,973 = A.D. 27
Age of Pisces ends and Aquarius begins = 27 + 2,148 = A.D. 2175
Pratt’s maximum offset = 29.38 degrees. (29.38/360) * 25,772 = 2,103
Age of Pisces begins = 2,000 – 2,103 - 1 = 104 B.C.
Age of Pisces ends and Aquarius begins = (-104) + 2,148 + 1 = A.D. 2045
So there you have it. No matter how you slice it, the Sixties hippies were jumping the gun. At best this is the morning twilight of the Age of Aquarius.