Vedic (Hindu) texts written in Sanskrit - in the Bhagavad Gita. (There were errors deliberately placed in the Yugas to hide the time cycles presumably from nefarious eyes.) The Yugas like astrological ages Pisces to Aquarius are based on the precession of the equinoxes.

Between 12 and 13,000 years ago the Satya Yuga (Ascending and Descending) were closest to the increased light source at the center of The Milky Way/ Now we near the tail of the Ascending Kali Yuga it is the least light, thus divisiveness etc.

But read this link first:

https://www.bibhudevmisra.com/2012/07/end-of-kali-yuga-in-2025-unraveling.html