The Mesoamerican Long Count is an ancient, non-repeating calendar used by some pre-Columbian peoples, including the Mayans.
Applying a tally that is vigesimal or centred on 20, rather than the pervading decimal system of ten that is still the international standard, the Long Count identified time by calculating the number of days that elapsed since a mythical creation date, generally corresponding to August 11, 3114 BCE or over 5000 years ago.
Left on stelae discovered in Central America, the calendar was built around a sophisticated mathematics system that may have started from merely counting on fingers and toes. The numerals consisted of only three symbols, crucially zero, represented as a shell shape; one, a dot; and five, a bar. Mesoamericans developed zero independently, working with sums up to the hundreds of millions. There is evidence of dates that are so extended and complex, they took several columns to record.
