Timekeeping, days, months, years
There are 3 elements of timekeeping;, days, a complete revolution of the earth, months, based on lunar full moon cycles, and years how long the earth takes to go around the Sun.
An Explanation of timekeeping from: https://en.wikipedia.org/wiki/History_of_calendars
The history of calendars, that is, of people creating and using methods for keeping track of days and larger divisions of time, covers a practice with ancient roots.
The natural units for timekeeping used by most historical societies are the day, the solar year and the lunation. Calendars are explicit schemes used for timekeeping. The first historically attested and formalized calendars date to the Bronze Age, dependent on the development of writing in the ancient Near East. The Sumerian calendar was the earliest, followed by the Egyptian, Assyrian and Elamite calendars.