when did humans start keeping track of years
History of calendars A number of prehistoric structures have been proposed as having had the purpose of timekeeping (typically keeping track of the course of the solar year). This includes many megalithic structures, and reconstructed arrangements going back far into the Neolithic period.
Paleolithic The Paleolithic (or "Palaeolithic")/ˌpæliːəˈlɪθɪk/ age is a prehistoric period of human history distinguished by the development of the most primitive stone tools and covers roughly 95% of human technological prehistory.[1] It extends from the earliest known use of stone tools, probably by Homo habilis initially, 2.6 million years ago, to the end of the Pleistocene around 10,000 BP.[2]