Most of us believe that at some finite moment, the universe began, creating at that moment the flow of Time, and that at some moment in the future Time will end. What came before Time, and what will come after Time is conceptualized as some kind of Eternal Unmoving Silent Absolute.
Modern science describes the beginning of Time as the “big bang” event and astro-physicists now measure energy from practically the second after the big bang occurred.
The ancient Vedic Seers talked about the repetitive cycle of the creation and destruction of universes as the day and night of Brahma, and they thereby inferred that the flow of Time we see in our universe is also present in the non-manifest periods between creative cycles.
We measure the events and the relationship of the different finite beings through the divisions of Time.
Of course, no one takes up, with this understanding of Time suddenly starting from an initial Timelessness, and eventually fading into a subsequent Timelessness, how this is to occur. What is it that starts the motion of Time if it was not there already? What brings Time to an end? And what starts it up again in the next cycle.
Sri Aurobindo provides a solution to this conundrum: “…if we look at existence as a whole, we see that infinite and finite co-exist and exist in and by each other. Even if our universe were to disappear and reappear rhythmically in Time, as was the old belief, that too woudl be only a large detail and would not show that at a particular time all condition ceases in the whole range of infinite existence and all Being becomes the unconditioned, at another it again takes on the reality or the appearance of conditions. The first source and the primary relations lie beyond our mental divisions of Time, in the divine timelessness or else in the indivisible or eternal Time of which our divisions and successions are only figures in a mental experience.”
reference: Sri Aurobindo, The Life Divine, Book 2, Part I, Chapter 3, The Eternal and the Individual, pg. 384