jan 1, 8000 BC - First calendar
Description:
A mesolithic arrangement of twelve pits and an arc found in Warren Field, Aberdeenshire, Scotland, dated to roughly 8,000 BC, has been described as a lunar calendar and was dubbed the "world's oldest known calendar" in 2013.[Added to timeline:
Date:
jan 1, 8000 BC
Now
~ 10032 years ago