The world’s oldest calendar is 10,000 years old and is made up of 12 pits that appear to mimic moon phases.
Archaeologists working in Scotland have uncovered what they believe to be the world’s oldest lunar calendar—a series of 12 large, specially shaped pits that were designed to mimic the various phases of the moon. The pits aligned perfectly on the midwinter solstice in a way that would have helped the hunter-gathers of Mesolithic Britain keep accurate track of the passage of the seasons and the lunar cycle.