The Maya calendar is a system of
distinct calendars and almanacs used by the Maya
civilization of pre-Columbian Mesoamerica, and by some
modern Maya communities in highland Guatemala.
These calendars can be synchronized and interlocked, their
combinations giving rise to further, more extensive
The most important of these calendars is one with a
period of 260 days commonly known as the Tzolkin, or Tzolk'in. The Tzolk'in is combined with another
365-day calendar (known as the Haab, or Haab' ), to
form a synchronized cycle lasting for 52 Haabs, called
the Calendar Round. Smaller cycles of 13 days (the
trecena) and 20 days (the veintena) were important
components of the Tzolk'in and Haab' cycles,
A different form of calendar was used to track longer
periods of time, and for the inscription of calendar
dates (i.e., identifying when one event occurred in
relation to others). This form, known as the Long
Count, is based upon the number of elapsed days since August 11, 3114 BCE.
By its linear nature, the Long Count was capable of
being extended to refer to any date far into the
future (or past).
Many Maya Long Count inscriptions are supplemented by
what is known as the Lunar Series, another calendar
form which provides information on the lunar phase and
position of the Moon in a half-yearly cycle.
A 584-day Venus cycle was also maintained, which
tracked the appearance and conjunctions of Venus as
the morning and evening stars. Many events in this
cycle were seen as being inauspicious and baleful, and
occasionally warfare was timed to coincide with stages
in this cycle.
Other, less-prevalent or poorly-understood cycles,
combinations and calendar progressions were also
tracked. An 819-day count is attested in a few
inscriptions; repeating sets of 9- and 13-day
intervals associated with different groups of deities,
animals and other significant concepts are also known.