A 10,000 year golden age is predicted in the Brahma-vaivarta Purana 4.129 by Krisna. Excerpts:
“On the earth 5,000 years of Kali will be sinful and sinners will deposit their sins in you by bathing.” Krisna, speaking to the river Ganges.
“Srimad-Bhagavatam (12.2.31) records Kali-yuga as having begun when the constellation of the seven sages (saptarsi) passed through the lunar mansion of Magha. Hindu astrologers have calculated this to have been 2:27 a.m. on February 20, 3102 BC. This took place some 36 years after Lord Krsna spoke Bhagavad-gita to Arjuna.”
— Vivek Rastogi on his blog
5000 years after 3102 BC would be about 1898 AD. Then…
Krisna goes on:
“Thereafter by the sight and touch of those who worship Me by My mantra, all those sins will be burnt.”
Note that he is not talking about thinking about him but experiencing him directly, by the sight and touch. This is thus not simple worship but direct experience. An awakening population for whom God is living.
“O Ganges, the whole planet will become a pilgrimage sight by the presence of Vaisnavas*, even though it had been sinful.”
“In the body of My devotees remains eternally [the purifier]. Mother Earth becomes pure by the dust of the feet of My devotees.”
“For 10,000 years of Kali such devotees of Mine will fill the whole planet. After the departure of My devotees there will be only one varna [outcast].”
It should be noted that when group consciousness is high enough, everyone will experience life as if enlightened. However, if one has not actually become Self Realized, when the age ends, the experience will be lost.
“Devoid of My devotees, the earth will be shackled by Kali. Saying this, Krsna departed.”
For the full translation of the section, see Vivek’s blog post.
*Vaisnavas = followers of Vishnu, of which Krisna is an avatar.