The last known date recorded on a Maya monument by their so-called Long Count calendar corresponds to the year 909.

The Long Count calendar is divided into units of 360 days called tuns.

It's unclear whether the Mayans created or simply adopted the Long Count calendar, a system that allowed them to uniquely record 1,872,000 consecutive days.

The idea that the world will end in 2012 is based on the Long Count calendar and its concept of Great Cycles.

For this reason, it is sometimes known as the Maya (or Mayan) Long Count calendar.

The Long Count calendar was widely used on monuments.

To designate dates over periods longer than 52 years, some Mesoamericans utilized the Long Count calendar.

There has been much debate over the precise correlation between the Western calendars and the Long Count calendars.

To specify dates over periods longer than 52 years, Mesoamericans used the Long Count calendar.

What collapsed quickly during the Classic collapse was the institution of kingship and the Long Count calendar.