Timeline of the universe.

From the authorative sources i.e Vedas , we get the above timeline for the existence of the universe. The point to be noted herein , is that the time line represented here is well organized and with accurate numbers. Hence the source can be taken to be authorative.

Explanation:

The timeline describes that Brahma the first living entity is the engineer and he is the one who engineers this universe,on the instructions of the Supreme Lord Krishna. So all the times are in reference to the life of Brahma. In short As long as brahma lives this universe lives, and when brahma dies, the universe is annhiliated completely.

The years mentioned are earthly years.

Brahmas 1 day (i.e 12 hours ) consists of 14 manvantaras
1 manvantara is the period where the father of living entities called manu generates all the living entities , and 1 manvantara consists of 71 divya yugas.

And 1 divya yuga comprises of 4 cycles , namely, satya yuga , treta yuga, dvapar yuga and kaliyuga.

Such is 1 day of bramha (i.e 12 hours) after the day of bramha, the night comes when brahma sleeps and the lower universes are sunk in the devastation water. After this night which is equal to the day comes yet another day of brahma where creation takes place.
In this way bramha lives for 100 years.

And after 100 years bramha dies and the universe is destroyed.

We currently are in kali yuga of the seventh manvantara as per the scriptures.