Age of Aquarius

The Age of Aquarius,in astrology, is either the current or forthcoming astrological age, depending on the method of calculation. Astrologers maintain that an astrological age is a product of the earth's slow precessional rotation and lasts for 2,160 years, on average (one "Great Year" equals 25,920-year period of precession / 12 zodiac signs = 2,160 years).
There are various methods of calculating the boundaries of an astrological age. In sun-sign astrology, the first sign is Aries, followed by Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces, whereupon the cycle returns to Aries and through the zodiacal signs again. Astrological ages proceed in the opposite direction ("retrograde" in astronomy). Therefore, the Age of Aquarius follows the Age of Pisces.
Overview.
The approximate 2,160 years for each age corresponds to the average time it takes for the vernal equinox to move from one constellation of the zodiac into the next. This average can be computed by dividing the earth's 25,800 year gyroscopic precession period by 12, the number of zodiacal signs. According to various astrologers' calculations, approximate dates for entering the Age of Aquarius range from 1447 CE (Terry MacKinnell) to 3597 CE (John Addey).
Astrologers do not agree on when the Aquarian age will start or even if it has already started. Campion (1999) lists various references from mainly astrological sources for the start of the Age of Aquarius. Based on Campion's summary, most published materials on the subject state that the Age of Aquarius arrived in the 20th century (29 claims), with the 24th century in second place with 12 claimants.
Astrological ages are taken to be associated with the precession of the equinoxes. The slow wobble of the earth's rotation axis on the celestial sphere is independent of the diurnal rotation of the earth on its own axis and the annual revolution of the earth around the sun. Traditionally this 25,800 year-long cycle is calibrated, for the purposes of determining astrological ages, by the location of the sun in one of the 12 zodiac constellations at the vernal (Spring) equinox, which corresponds to the moment the sun crosses the celestial equator, marking the start of spring in the Northern Hemisphere each year. Roughly every 2,150 years the sun's position at the time of the vernal equinox will have moved into a new zodiacal constellation.
In 1929 the International Astronomical Union defined the edges of the 88 official constellations. The edge established between Pisces and Aquarius officially locates the beginning of the Aquarian Age around 2600 CE. Many astrologers dispute this approach because of the varying sizes and overlap between the zodiacal constellations. They prefer the long-established convention of equally-sized signs, spaced every 30 degrees along the ecliptic, which are named for the 12 background zodiacal constellations.
Astrological meaning.
Astrologers believe that an astrological age affects humanity, possibly by influencing the rise and fall of civilizations or cultural tendencies. 
Traditionally, Aquarius is associated with electricity, computers, flight, democracy, freedom, humanitarianism, idealism, modernization, astrology, nervous disorders, rebellion, nonconformity, philanthropy, veracity, perseverance, humanity, and irresolution.
The variations of views among astrologers include:
Common cultural associations.
The expression "Age of Aquarius" in popular culture usually refers to the heyday of the hippie and New Age movements in the 1960s and 1970s.
The 1967 musical "Hair", with its opening song "Aquarius" and the line "This is the dawning of the Age of Aquarius", brought the Aquarian age concept to the attention of audiences worldwide. However, the song further defines this dawning of the age within the first lines: "When the Moon is in the seventh house and Jupiter aligns with Mars, then peace will guide the planets and love will steer the stars". Astrologer Neil Spencer denounced the lyrics as "astrological gibberish", noting that Jupiter aligns with Mars several times a year and the Moon is in the 7th House for two hours every day.
These lines are considered by critics to be poetic license, though some people have taken them literally. An example is the identification of Valentine's Day 2009 as the "perfect alignment to support our collective manifestation of love and peace and dawning of the Age of Aquarius". In popular culture, the NBC television show "Aquarius", which premiered on May 28, 2015, is based on the Charles Manson case. The name relates to the "dawn of Aquarius," also commonly referred to as the New Age way of thinking.
The music festival commonly known as Woodstock was billed as "An Aquarian Exposition".