in 427.000 yrs its a cycle of four time periods Satya, Dvapara, Treta and Kali yuga, Kali being the shortest and the others twice as long incrementally backwards.
Kali yuga is called the iron age. It's time when humans degrade down to living like animals and have lost their connection with God.
One thousand such cycles is one day for Lord Brahma. The creator of the material world. Brahma is a position, like prime minister. The universe exist for one hundred of Brahmas years.
There exist innumerable universes and they all emanate from the pores of Lord Vishnu, lying down in causal ocean, when he exhales. When he inhales they return again. The time span for our universe equals one of his breaths.
But there is hope :) it is predicted that there will occur a period of spiritual awakening before all goes downwards.