Mbh 3.187.2a

“Markandeya replied, ‘Indeed, I shall explain all, after having bowed down to that Self-existent, Primordial Being, who is eternal and undeteriorating and inconceivable, and who is at once vested with and divested of attributes. O tiger among men, this Janardana attired in yellow robes is the grand Mover and Creator of all, the Soul and Framer of all things, and the lord of all! He is also called the Great, the Incomprehensible, the Wonderful and the Immaculate. He is without beginning and without end, pervades all the world, is Unchangeable and Undeteriorating. He is the Creator of all, but is himself uncreate and is the Cause of all power. His knowledge is greater than that of all the gods together. O best of kings and pre-eminent of men, after the dissolution of the universe, all this wonderful creation again comes into life. Four thousand years have been said to constitute the Krita Yuga. Its dawn also, as well as its eve, hath been said to comprise four hundred years. The Treta-Yuga is said to comprise three thousand years, and its dawn, as well as its eve, is said to comprise three hundred years. The Yuga that comes next is called Dwapara, and it hath been computed to consist of two thousand years. Its dawn, as well as its eve, is said to comprise two hundred years. The next Yuga, called Kali, is said to comprise one thousand years and its dawn, as well as eve, is said to comprise one hundred years. Know, O king, that the duration of the dawn is the same as that of the eve of a Yuga. And after the Kali Yuga is over, the Krita Yuga comes again. A cycle of the Yugas thus comprised a period of twelve thousand years. A full thousand of such cycles would constitute a day of Brahma. O tiger among men, when all this universe is withdrawn and ensconced within its home--the Creator himself--that disappearance of all things is called by the learned to be Universal Destruction.