Yuga

Yuga in Hinduism is an epoch or era within a four age cycle. A complete Yuga starts with the Satya Yuga, via Treta Yuga and Dvapara Yuga into a Kali Yuga. Our present time is a Kali Yuga, which started at 3102 BCE with the end of the Mahabharata war.

There are four Yugas in one cycle:

According to the Laws of Manu, one of the earliest known texts describing the yugas, the lengths are 4800 years + 3600 years + 2400 years + 1200 years, for a total of 12,000 years for one arc, or 24,000 years to complete the cycle, which is approximately one precession of the equinox. These 4 yugas follow a timeline ratio of (4:3:2:1).

According to Srimad Bhagavatam 3.11.19, which is dated at 200 BCE-200CE, the Yugas are much longer, using a divine year in which one day is equal to one human year, thus:

one year of the demigods is equal to 360 years of the human beings. The duration of the Satya-yuga is therefore 4,800 x 360, or 1,728,000 years. The duration of the Tretā-yuga is 3,600 x 360, or 1,296,000 years. The duration of the Dvāpara-yuga is 2,400 x 360, or 864,000 years.

The Viṣṇu Purāṇa Time measurement section of the Viṣṇu Purāṇa Book I Chapter III adds:

While the long yuga count is the most popular, it does not correlate to any known celestial motion found in the Astronomical Almanac. The value of 24,000 years fits relatively close with the modern astronomical calculation of one full precession of the equinox, which takes 25,772 years. Thus the yuga cycle may have some basis in known terrestrial cycles. Srimad Bhagavatam 3.11.19 describes the timespans of the demigods, in which a year of a yuga is a year of the demigods. It is this second sloka which appears to have been modified over the years.

According to Brahma Kumaris, total duration of four yuga (stages of world cycle) is 5000 years, of which each yuga (stages of world cycle) is 1250 years.

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