The time-cycle of creation is that each Chatur-Yuga is 43,20,000 years, split up as such:
1 deva day = 1 human year.
1 deva year = 360 deva days.
1 deva year = 360 human years.
Each Yuga is calculated in certain number of deva years plus a tenth of it before and after called sandhis.
kali yuga = 1200 deva years = 100 pre-sandhi + 1000 + 100 post-sandhi
dwapara = 2 x Kali = 2400 deva years = 200 pre-sandhi + 2000 + 200 post-sandhi
treta = 3 x Kali = 3600 deva years = 300 pre-sandhi + 3000 + 300 post-sandhi
krita = 4 x Kali = 4800 deva years = 400 pre-sandhi + 4000 + 400 post-sandhi
So does that mean that when Sri Krishna left earth, the post-sandhi period of Dwarapa Yuga (200 deva years) got completed, and now we are in the pre-sandhi period of Kali Yuga (100 deva years)?
100 deva years = 36,000 human years. Of which we are currently (2018) in year 5120.
Does that mean Kali-Yuga-Proper (after pre-sandhi period is over) doesn't start until 31000 years from now?
Note - Some people assume that these numbers (1000, 2000 etc.) are in human years, but they're not.