In the "Brahma-Vaivarta Purana", Lord Krishna tells Ganga Devi that a Golden Age will come in the Kali Yuga, One of the four stages of development that the world goes through as part of the cycle of eras, as described in Hindu scriptures.
Lord Krishna predicted that this Golden Age will start 5,000 years after the beginning of the Kali Yuga, and will last for 10,000 years.
Source : alamongordo