If the world, the Universe, or the Multiverse, has a beginning, then its substance must exist in the form of a spatially finite physical reality, possessing the necessary potential. Obviously, it is hard to believe that it arose from absolute Nothing. Therefore, it has existed eternally, and at a certain moment, it spontaneously began to self-organize, thereby ending its epoch. Hence the corresponding question: "What can be said about the concept of time during the period of existence of this substance?"
