The beginning date of the Long Count corresponds to the equivalent of August 11, 3114 B.C. in our calendar. However, the first recorded inscriptions of the Long Count actually appear around 35 B.C. at the pre-Maya sites of Chi-apa de Corzo and Tres Zapotes. This was some 300 years before the Maya emerged as a fully fledged culture, so the Long Count wasn't their invention.

One of the great mysteries of these early Mesoamerican cultures is how the calendar reached such a remarkable state of development right at the beginning of their recorded history. The Maya inherited this knowledge, but they took its application to spectacular new heights.

Over time, the Long Count calendar spread from city-state to city-state across the Maya lands. Its influence eventually reached from Chiapas in the west to Guatemala in the east and the Yucatán peninsula in the north.

The propagation and development of the Long Count was to become one of the greatest cultural achievements of the Maya. It became a defining characteristic of what it meant to be Mayan. City-states and their rulers competed to create the most ornate monuments and statues, incorporating significant and auspicious dates of accessions and conquests.

Some of these intricately carved statues are huge, up to 25 feet in height, and contain many elaborate inscriptions on all four sides. The artistry of Maya carving, for example at Copan and Quirigua, is surpassed in technique and scale only by the monumental works of the ancient Egyptians.

The Long Count effectively became the unifying symbol of a remarkable civilization that flourished between A.D. 300 and A.D. 900. This was the classic era of the Maya, when they built their most spectacular pyramids and ceremonial centers. At this time, Mayan culture was equal to or surpassed the accomplishments of any other contemporary civilization, including those in Europe.

Around A.D. 900, for reasons still debated, the Maya started to abandon their cities. The most popular explanation of what happened is that their form of slash-and-burn agriculture used for the cultivation of corn and other crops led to an ecological collapse. As a result, they could no longer feed their population.

After the classic-era Mayan decline, the surviving Mayan cities were more open to attack and invasion. The coming of the Mexica and Itzá to the Yucatán peninsula marked the end of this pure form of Mayan civilization. Widespread usage of the Long Count calendar probably only survived for 100 years after this point.

After this, under cultural pressure from their invaders, the Maya began to radically shorten the time periods they were interested in recording. Sometime before the European invasion, knowledge of the Long Count was completely lost.

The structure of the calendar is very unusual and there are no known parallels to it in the calendars of any other cultures. The Long Count is made up of a total of five different units, but it is really just a count of days.

Each of the increasingly bigger units represents a multiple of the number of days. It does have a unit called the tun that is 360 days long — a rough approximation to a year's length — but the Long Count doesn't have a New Years day and it isn't tied to a particular starting day of the solar year.

Each tun consists of 18 uinals of 20 days each. This is exactly the same structure as the Haab calendar we looked at in the last chapter, where 18 twenty-day uinals make up the main lucky 360-day part of the year. Twenty of these 360-day tuns make a bigger unit called a katun that lasts approximately 19.71 years. The katun cycle was given a great deal of importance for the Maya in making prophetic predictions and each katun had its own qualities and characteristics.

Twenty of these katuns make up one baktun. Each baktun was a period of close to 400 years — 394.25 years, to be more exact. The whole cycle consists of exactly thirteen baktuns in total. This can be further subdivided into 260 katuns. These, in turn, contain a total 5,200 tuns, the equivalent of 5,125.37 years.

The different units of the Long Count are:

• Kin: 1 day

• Uinal: 20 days

• Tun: 18 × 20 days = 360 days

• Katun: 20 × 360 days = 7,200 days

• Baktun: 20 × 7,200 days = 14,4000 days

• Thirteen Baktuns: 13 × 14,4000 = 1,872,000 days

A particular day in the Long Count is written as a series of all of these units, starting with the biggest number first (baktuns) and working downward to the number of days that have passed in the uinal. The first day of the thirteen baktuns was written 0.0.0.0.0 in this form of notation. The last day will be 13.0.0.0.0. It is widely agreed that the thirteen baktuns began on August 11, 3114 B.C. and that they will end on December 21, 2012. To make the dates complete, the Tzolkin and Haab dates are added to the end of the Long Count.

The beginning of the Long Count:

August 11, 3114 b . c . = 0.0.0.0.0 4 Ahau, 8 Cumku

The end of the Long Count:

December 21, a . d . 2012 = 13.0.0.0.0. 4 Ahau, 3 Kankin

One of the earliest known inscriptions on a dated monument of the classic Mayan period was found at Tikal. It records the date of July 6, A.D. 292, or 8.12.14.8.15 in the notation of the Long Count. That's equivalent to eight baktuns, twelve katuns, fourteen tuns, eight uinals, and fifteen kin from the start of the Long Count — 1,243,615 days.

One of the last recorded dates of the classic period was carved on a stele at the site of San Lorenzo. This was inscribed with the date of 10.5.0.0.0., or October 5, A.D. 928. That's ten baktuns, five katuns, and no tun, uinals, or kin — a date exactly 1,476,000 days after the beginning of the count. This was a particularly important day in the calendar, as it marked the ending of a twenty-year katun. At that time, the statue of the god of the old katun would have been replaced in the Mayan calendar temple with a statue of the new one, signifying the changeover from one period to another.