The prominent way of counting time is the way of the continent of Myaasia. No one knows why it is as it is, but still it is almost universally used by humans, and most others at least know how to use it.
Time is divided into seconds, minutes, hours, days, weeks, years, periods, sets and eras.
Seconds to weeks is as expected. There are 48 weeks in a year and 12 years in a period, except in the periods of destruction that thankfully only have six years. A set has 13 periods and thus 150 years.
Catalysmic events cause the change of an era and the counting of periods to start anew.

When a new era is started by the collapse of civilisation, the counting of years is 12 years of beaver, followed by 12 years of badger and so on until there are the six years of destruction.
These periods are collectively called the “first periods,“ totaling 150 years followed by the “second periods” and so on.

The weeks of a year are all named and have a “theme.” The years of a period are numbered, and the periods are also named and have an “ideal.” Thus time is given as “11 in the morning of sunday of strength in the year four of seventh period of wolf in third era.”
This means “11 a.m. on Sunday of the 28th week of the year, in the fourth year in 12th period(=year 136 of the set) in the seventh set in the third era(=year 1.036 of the era).”

The names of weeks are a mystery as they do not seem to fit the seasons or any other logic.