The World is Made of Events, not Things. - Carlo Rovelli

The thermal time hypothesis. In nature, there is no preferred physical time variable t. There are no equilibrium states ρ₀ preferred a priori. Rather, all variables are equivalent; we can find the system in an arbitrary state ρ; if the system is in a state ρ, then a preferred variable is singled out by the state of the system. This variable is what we call time.

If I move one watch, put it higher, and wait a little bit... with very good clocks, and today we can... you bring it [back] down, and this [the clock that was higher] is ahead, this [the clock that remained lower] is behind. ...The clock up, has measured more time than the clock down. And it's not just a matter of clocks. Everything, ...if you are high ...a flower would blossom more, a machine would do more cycles ...more things happening up than down. Of course, the difference is small, otherwise we would have noticed it ...earlier.

[I]t is the statistical state that determines which variable is physical time, and not any a priori hypothetical "flow" that drives the system to a preferred statistical state. When we say that a certain variable is “the time”, we are not making a statement concerning the fundamental mechanical structure of reality. Rather, we are making a statement about the statistical distribution we use to describe the... properties of the system... The "thermal time hypothesis" is the idea that what we call "time" is the thermal time of the statistical state in which the world happens to be, when described in terms of the macroscopic parameters we have chosen.