The Maya erected stelae—i.e., stone slabs or pillars—on which they carved representative figures and important dates and events in their rulers’ lives. To describe a given date more accurately, the Maya instituted the “Long Count,” a continuous marking of time from a base date. The Calendar was the base date used by the Maya for the start of the “Long Count” and the first “Great Cycle,” a period of 5,125 years that ends on December 21, 2012 CE.