The numerous and profoundly distinct layers that make up the notion of time

Much confusion and disagreement around the notion of time is due to the fact that we commonly fail to recognize that we call “time” a variety of distinct notions, only partially related to one another. Many “obvious” properties of time are actually results of different kinds of approximations, idealizations, or special contexts. I illustrate a number of distinct notions of time and their differences; they are all relevant for describing the real world. To understand time, we have to break it apart