Maya Long Count calendar
The Maya Long Count calendar records dates as elapsed days from a fixed starting point, using a place-value count organized into named periods.
Maya numerals: A base-20 positional numeral system used by the ancient Maya, with a shell-shaped zero symbol. Its bars, dots, and zero encode the Long Count’s period values.
Tzolk'in: A 260-day Maya calendrical cycle combining 13 numbers with 20 day names. It formed one half of the Maya Calendar Round used alongside Long Count dates.
Maya civilization: The societies and political states of the Maya peoples, whose history spans Mesoamerica from antiquity to the present. Maya communities developed and used the Long Count across different periods and regions.
Maya astronomy: The observation and mathematical recording of celestial cycles by ancient Maya communities. Long Count dates helped situate observations and events within extended timelines.
2012 phenomenon: Modern media and cultural interpretations of the Maya Long Count’s transition at the end of 2012. The completion of a baktun became the focus of claims the calendar itself did not make.
K'in: A day, the basic unit counted by the Maya Long Count. Every Long Count date ultimately expresses a number of k'ins elapsed.
Haab': A 365-day Maya solar calendar composed of 18 periods of 20 days and a five-day period. Its annual cycle paired with the Tzolk'in to identify recurring dates.
San Bartolo murals: Late Preclassic Maya wall paintings discovered at San Bartolo, Guatemala, including early calendrical writing. Their dates and inscriptions provide evidence for early development of Maya calendrical practice.
Maya inscriptions: Texts written in Maya scripts on monuments, ceramics, and other materials. Long Count dates anchor many inscriptions describing rulers, rituals, and events.
December 21, 2012: A date associated with the completion of 13 baktuns in the Maya Long Count under the GMT correlation. It marked a major period boundary, not an established prediction of world destruction.