Kali Yuga, in Hinduism, is the fourth and worst of the four yugas (world ages) in a Yuga Cycle, preceded by Dvapara Yuga and followed by the next cycle's Krita (Satya) Yuga. It is believed to be the present age, which is full of conflict and sin.
According to Puranic sources, Krishna's death marked the end of Dvapara Yuga and the start of Kali Yuga, which is dated to 17/18 February 3102 BCE. Lasting for 432,000 years (1,200 divine years), Kali Yuga began years ago and has years left as of CE. Kali Yuga will end in the year 428,899 CE.
Near the end of Kali Yuga, when virtues are at their worst, a cataclysm and a re-establishment of dharma occur to usher in the next cycle's Krita (Satya) Yuga, prophesied to occur by Kalki.
Yuga (युग), in this context, means "an age of the world", where its archaic spelling is yug, with other forms of yugam, , and yuge, derived from yuj (), believed derived from (Proto-Indo-European: 'to join or unite').
Kali Yuga (kaliyuga or kali-yuga) means "the age of Kali (demon)", "the age of darkness", "the age of vice and misery", or "the age of quarrel and hypocrisy".
A complete description of Kali Yuga is found in the Mahabharata, Manusmriti, Vishnu Smriti, and various Puranas. It is used mathematically in the astronomical texts Aryabhatiya and Surya Siddhanta.
According to P. V. Kane, one of the earliest inscriptions with one of the four yugas named is the Pikira grant of Pallava Simhavarman (mid-5th century CE):
Who was ever ready to extricate dharma that had become sunk owing to the evil effects of Kaliyuga.
Other epigraphs exist with named yugas in the Old Mysore region of India, published in Epigraphia Carnatica.
According to the Surya Siddhanta, Kali Yuga began at midnight (00:00) on 18 February 3102 BCE. This is also considered the date on which Krishna left the earth to return to Vaikuntha. This information is placed at the temple of Bhalka, the place of this incident (see photo).
According to the astronomer and mathematician Aryabhata, Kali Yuga started in 3102 BCE.