Three hundred and sixty human years equal one God year. Thus 12,000 God years equal 4,320,000 man years. Satya Yug, Tret Yug, Dvapar Yug and Kali Yug. In addition ,there are other time periods between these four Yugas. Adding up the four Yugas and the Sandhyamsh we get a total of 4,320,000 man years or a Maha Yuga.
Ignorance never carries an answer.
At least not the truth. Thus there are 296,720,000 man years in a Manvantr. Thus there are 4,320,000,000 man years in a Kalp. Between the time he opens his eyes- to start all over again. Time between creation and destruction.