The difference between past and future... cause and effect... memory and hope... regret and intention... in the elementary laws that describe the mec… - Carlo Rovelli

[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.

The idea that a well-defined now exists throughout the universe is an illusion, an illegitimate extrapolation of our own experience

Time is... the expression of our ignorance of the full microstate.