In the context of an expanding universe, the passage of time is indeed closely related to the expansion of spacetime. However, it's important to note that the concept of time and its relationship with the expansion of the universe can be quite complex and is still an area of active research and study in cosmology and theoretical physics.
According to the theory of general relativity, which describes gravity as the curvature of spacetime, the expansion of the universe is associated with the stretching of space itself. As the universe expands, the distances between galaxies, clusters of galaxies, and other cosmic structures increase.
This expansion of space can have implications for the measurement of time. In a homogeneous and isotropic expanding universe, a phenomenon known as cosmological time dilation occurs. This means that as the universe expands, the interval of time between events can increase. In other words, clocks in regions that are receding from each other due to the expansion will measure longer durations between the same events compared to clocks in regions that are not receding from each other.
However, it's important to understand that the concept of time in cosmology is more intricate than just the expansion of spacetime. There are other factors to consider, such as the presence of matter and energy, the curvature of spacetime, and the influence of other physical processes.
Furthermore, the nature of time itself is a complex topic in physics, and various philosophical and scientific discussions exist on its fundamental nature and whether it is an emergent property or a fundamental aspect of reality.
In summary, while the expansion of spacetime in an expanding universe is related to the passage of time, the relationship between time and the expansion of the universe is multifaceted and involves various aspects of cosmology, general relativity, and the nature of time itself.