Demigods

"The duration of the Satya millennium equals 4,800 years of the years of the demigods; the duration of the Dvapara millennium equals 2,400 years; and that of the Kali millennium is 1,200 years of the demigods.

PURPORT

As aforementioned, one year of the demigods is equal to 360 years of the human beings. The duration of the Satya-yuga is therefore 4,800 x 360, or 1,728,000 years. The duration of the Treta-yuga is 3,600 x 360, or 1,296,000 years. The duration of the Dvapara-yuga is 2,400 x 360, or 864,000 years. And the last, the Kali-yuga, is 1,200 x 360, or 432,000 years."

"The years of the demigods are equal to 360 years of humankind. As will be clarified in the subsequent verses, 12,000 of the demigods' years, including the transitional periods which are called yuga-sandhyas, comprise the total of the aforementioned four millenniums. Thus the aggregate of the above-mentioned four millenniums is 4,320,000 years."