According to Hinduism, the are 4 yugas, Satya, Treta, Dwapra and Kali which repeat endlessly in a cycle each time the universe is destroyed at the end of Kali Yuga and reborn again to give birth to Satya Yuga. The belief is, that as the Yugas progress from Satya to Kali, the human life span decreases by an order of magnitude with each yuga, declining from 100000 years in satya yuga to a mere 100 years in Kali. This decline in longevity is accompanied by a decline in morality and values. Dharma was famously compared to a cow to illustrate this – Puranic sources say that the dharmic cow which started with 4 legs in the first Yuga keeps losing a leg in each Yuga until its left standing on a single leg in Kali Yuga. The Kali Yuga is expected to end when the Kalki avatar appears. You can read an interesting back story here.
The Treta yuga is supposedly 1,296,000 years long and the Dwapra yuga is supposed to be 864,000 years long. Nina thinks Nana might well be from the Treta yuga but I still wonder how old he really is. Any guesses?
You can read Kanika’s take here.