The change of cycles of time, if one understands Hindu Cosmology in its true sense, marks the period when the human consciousness undergoes a total change. The changed human is an advanced model of the last model; just like cars or mobiles.
This cycle preserves only those who are in the process of change or trying to look and find the natural evolutionary cycle; these elements are recycled and taken to next stage. The rest are discarded and scrapped like virus affected and broken down computers. The Cosmic Mind cleanses itself of the mutations and morbidity; the blockages in the natural flow of evolution and returns to its natural state.
The end of this cycle is as per Hindu Cosmology is to be heralded in by the 10th and last of Vishnu’s Avatars; the Kalki Avatar. Though there is no agreement about the period and timing of his descent upon Earth, it could come anytime as the conditions are rapidly deteriorating and resembling those mentioned in the Puranas. Those trying to arrive at dates when the Kalki Avatar is coming should be advised to remember that they are too insignificant to decode the Cosmic Being.
I am inclined to believe that the coming of the Kalki Avatar will be right out of the blue, when no one expects it. Researchers should give up trying to decode the exact date of the coming as they are too small to understand the working of the Cosmic Mind.