What is the duration of Kali Yuga? ⌛⏳

Srimad Bhagavatam says,

"Two solar movements make one day and night of the demigods, and that combination of day and night is one complete calendar year for the human being. The human being has a duration of life of one hundred years." (3.11.12)

"The duration of the Satya millennium equals 4,800 years of the years of the demigods; the duration of the Tretā millennium equals 3,600 years of the demigods; the duration of the Dvāpara millennium equals 2,400 years; and that of the Kali millennium is 1,200 years of the demigods." (3.11.19)

One year of the demigods is equal to 360 years of the human beings. The duration of the Satya-yuga is therefore 4,800 × 360, or 1,728,000 years. The duration of the Tretā-yuga is 1,296,000 years. The duration of the Dvāpara-yuga is 864,000 years. And the last, the Kali-yuga, is 432,000 years. We are currently 5,120 years into Kali-yuga, within the 10,000 golden age at the beginning of Kali-yuga where Visnu-bhakti is still present, so the effects of Kali have yet to become fully manifest (Brahma-vaivarta Purana 4.129.49-60).

Extra information:

Pralaya(Destruction) happens at the end of one Kalpa.

After end of a yuga another yuga comes.

And Lord kalki would facilitate the transition from kaliyuga to satyug.

Here is the timeline.

1 kalpa = 14 Manvantra

1 Manvantar = 71 MahaYuga

1 Mahayuga = All four Yugas + some additional time.

So after one kalpa(day of brahma) Lord Rudra would dissolve the world into himself.

When lord brahma attains the age of 100 years.

Mahapralaya happens in which even lord brahma is dissolved in Lord Shiva.