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.
Anatomically modern human Homo sapiens evolved from "archaic" or "robust" predecessors (Homo heidelbergensis, or a related offshoot from Homo erectus) around 315,000 years ago. The divergence of modern human populations dates to shortly after this time, the oldest division being that of the hunter-gatherer populations of Southern Africa, although there have been numerous events of admixture both among modern populations and between modern and archaic ones.