There are three different notions of metaphysical time that are associated with mathematical concepts, substantivalism and modal relationism. One argument suggests that time is necessarily related to physical systems that can act as clocks. Another discussion focuses on the physical basis of the time concept in cosmology and the idea that the physical basis is connected to physical processes that could occur. Additionally, there is no "before" the universe in terms of time. A paper analyzes the physical basis for time in cosmology and addresses issues of a well-defined concept. It also examines philosophical and conceptual issues related to the search for a quantum theory of gravity. The author argues that fundamental physical theories describe different levels of physical reality, but metaphysical arguments against the flow of time may be flawed.