The Vishnu Purana
Chapters
The Vishnu Purana: Book IV: Chapter XXIV

rise in the heavens, and some lunar asterism is seen at night at an equal distance between them, then the seven Rishis continue stationary in that conjunction for a hundred years of men 82. At the birth of

[paragraph continues] Paríkshit they were in Maghá, and the Kali age then commenced, which consists of 1200 (divine) years. When the portion of Vishńu (that had been born from Vasudeva) returned to heaven, then the Kali age commenced. As long as the earth was touched by his sacred feet, the Kali age could not affect it. As soon as the incarnation of the eternal Vishńu had departed, the son of Dharma, Yudhisht́hira, with his brethren, abdicated the sovereignty. Observing unpropitious portents, consequent upon Krishńa's disappearance, he placed Paríkshit upon the throne. When the seven Rishis are in Purváshád́há, then Nanda will begin to reign 83, and thenceforward the influence of the Kali will augment.

The day that Krishńa shall have departed from the earth will be the first of the Kali age, the duration of which you shall hear; it will continue for 360,000 years of mortals. After twelve hundred divine years shall have elapsed, the Krita age shall be renewed.

Thus age after age Brahmans, Kshatriyas, Vaiśyas, and Śúdras, excellent Brahman, men of great souls, have passed away by thousands; whose names and tribes and families I have not enumerated to you, from their great number, and the repetition of appellations it would involve. Two persons, Devápi of the race of Puru, and Maru of the family of Ikshwáku, through the force of devotion continue alive throughout the whole four ages, residing at the village of Kalápa: they will return hither in the beginning of the Krita age, and, becoming members of the family of the Manu, give origin to the Kshatriya dynasties 84. In this manner the earth is possessed through every series of the three first ages, the Krita, Treta, and Dwápara, by the sons of the Manu; and some remain in the Kali age, to serve as the rudiments of renewed generations, in the same way as Devápi and Maru are still in existence.