In an interesting podcast featuring one Nilesh Oak, a historian by profession, he describes the concept of yugas, as mentioned in a part of the Aitreya Brahmana.
Now typically yugas are considered to be large time periods, and some of the dating doesn’t even make sense.
For instance, the common number one sees is that some 432,000 years makes up one yuga. And some will compound this number as well. And then they say the Mahabharata happened one yuga ago, so 432,000 years ago. Really? Was there even any human life back then?
And thus this different explanation of yugas was symbolic and interesting, as are most things in Hinduism! What did it say?
That when we sleep, that is Kali Yuga. When we wake up and sit, it is Treta Yuga. When we stand, it is Dwapara Yuga, and when we take action, it is Satya Yuga!