n. In Hindu theology, an epoch or era within a cycle of four ages: the Satya Yuga (or Krita Yuga), the the Dvapara Yuga, the Treta Yugaand finally the Kali Yuga, with incremental lengths ranging from 432,000 to 1,728,000 years.
Word Usage
"And since each “year” equals 360 earth years, one yuga cycle equals 4.32 million years while a thousand yuga cycles total 4.32 billion years, summing up the Day of Brahma."