Mesoamerican calendars was of ritual significance to a number of Mesoamerican cultures. A third major calendar form known as the Long Count is found in the inscriptions of several Mesoamerican cultures, most famously those of the Maya civilization who developed it to its fullest extent during the Classic period (ca. 200–900 CE). The Long Count provided the ability to uniquely identify days over a much longer period of time, by combining a sequence of day-counts or cycles of increasing length, calculated or set from a particular date in the mythical past. Most commonly, five such higher-order cycles in a modified vigesimal (base-20)
Mesoamerican writing systems skin covered with stucco. These codices are read in boustrophedon, a zigzag style in which the reader follows red lines that indicate the way to read. Most of the current knowledge about the writing of the Mixtecans is due to the work of Alfonso Caso, who undertook the task of deciphering the code based on a set of pre-Columbian and colonial documents of the Mixtec culture. Although the Mixtecs had a set of symbols that allowed them to record historical dates, they did not use the long count calendar characteristic of other southeast Mesoamerican writing systems. Instead, the codices that