The alleged two-thousand year long period in human history marked by enlightenment, love, and profound peace heralded by the ascension of the constellation of Aquarius into 'the house of the Sun' in "astrology". Astrologers through out history have disputed the time frame in which this period of universal enlightenment is set to begin, with most estimates falling between 1904 and 2160 AD. The term received its greatest popularity during the 1960s when spiritual exploration and alternative lifestyles became fashionable in society because of the political and social unrest of the time. See also "New Age".
This term refers to the fact that the beginning of Aries (measured by the April equinox) has gradually shifted against the backdrop of the fixed stars (see Precession of the Equinoxes). This Aries point has travelled backwards through the sign of Pisces (the sign before Aries) and is about to move into Aquarius (the sign before Pisces). Since there are different ways of measuring where Aquarius ends and Pisces begins, it is not possible to calculate a specific date for when the Age of Aquarius begins. However, since there are about 2,000 years per zodiacal Age, the transition is likely to be a gradual one anyway. See also: Precession of the Equinoxes.