Zothecula writes: While we take calendars for granted these days, the invention of systems that track time stands as one of humanity's most monumental achievements
... in more ways than one. Long before written calendars emerged, monuments were used to measure time. Now a crude but working "calendar" discovered in Warren Field, Scotland, suggests that these time measuring monuments may have been developed much earlier than previously thought. Archaeologists believe the Warren Field calendar was created by hunter gatherers around 8,000 BC, making it the world's oldest calendar discovered to date by a significant margin.