Detail showing three columns of glyphs from a portion of the 2nd century CE La Mojarra Stela 1.The left column gives a Long Count date of, or 156 CE.

The two most widely used calendars in pre-Columbian Mesoamerica, were the 260-day Tzolk'in and the 365 day Haab'.

The equivalent Aztec calendars are known in Nahuatl as the tonalpohualli and Xiuhpohualli.

The two right columns visible are glyphs from the Epi-Olmec script.

The Long Count calendar identifies a date by counting the number of days from a starting date that is generally calculated to be August 11, 3114 BCE in the proleptic Gregorian calendar or September 6 in the Julian calendar (or −3113 in astronomical year numbering).

Long Count dates are written with Mesoamerican numerals, as shown on this table. The shell glyph was used to represent the zero concept.

The Long Count calendar required the use of zero as a place-holder and presents one of the earliest uses of the zero concept in history.

The text then continues with whatever activity occurred on that date.

A drawing of a full Maya Long Count inscription is shown below.

The numbered Long Count was no longer in use by the time the Spanish arrived in the Yucatán Peninsula, although unnumbered k'atuns and tuns were still in use.

Instead the Maya were using an abbreviated Short Count.

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