kali yuga (Sanskrit: कलियुग, "age of Kali"; "age of vice") — is one of the four stages of development that the world goes through as part of the cycle of Yugas, the others being satya-yuga, treta-yuga and dwapara-yuga.
The human civilization degenerates spiritually throughout the Kali Yuga — it is mostly referred to as the Dark Age, mainly because people are the furthest possible from Divinity. During the Kali Yuga righteousness has diminished by three-quarters, and the age is one of devolution, culminating in the destruction of the world prior to a new creation and another Krita Yuga in an endless cycle of time.
Kali Yuga Timeline
Since a year of the devas equals 360 years of men, the extent of Kali Yuga is 432,000 years;
According to the Surya Siddhanta, an astronomical treatise that forms the basis of all Hindu and Buddhist calendars, Kali Yuga began at midnight (00:00) on 18 February 3102 BCE in the proleptic Julian calendar or 23 January 3102 BC in the proleptic Gregorian calendar.
In The Aihole Inscription 3735 years after the Bharata war is equated with 556 years of the Saka Era, in the Kali Yuga. This would mean 3179 years after the Bharata war, the Saka Era started. Whitaker’s alamanac says that Year 1922 in the Saka calendar is 2000 AD/CE. So the Saka year started in 78 BC. That would imply that the Kaliyuga started in 3179-78= 3101 BC.