The Long Count is a linear timekeeping method of the Maya. Unlike the Haab and Tzolkin the Long Count does not start over. Instead, it has a starting date -- the date of the current world’s creation -- and keeps increasing forever. In a way it is like how we count the years, although we do it in terms of AD and BC.
By using the Long Count, the ancient Maya were able to keep track of dates in a larger context than they could with just the Calendar Round. This makes them different from other cultures that just used the Calendar Round, such as the Aztecs.
The oldest Long Count dates thus far discovered in the Maya world are located in the southern area and date from the Late Preclassic period. From this time, it seems that use of the Long Count spread to the Maya lowlands by the Classic period.
Set Up of the Long Count
Parts of the Long Count include:
Kin -- this is equal to one day.
Uinal -- this is equal to 20 kin. 18 uinals made a tun.
Tun -- a 360-day period made of 18 uinals (or uinics**).
Katun -- a period of 20 tuns which equals 7,200 days.
Baktun -- a period of 20 katuns or 144,000 days.
The Maya also had larger periods time, but they were not used in the Long Count. These are:
Pictun -- a period of 20 baktuns.
Calabtun -- a period of 20 pictuns.
Cinchiltun -- a period of 20 calabtuns.
Alawtun -- a period of 20 cinchiltuns.
Most of the names are not the original names the Maya used. They are names that they were given in more recent times.
Transliterating the Long Count
The Long Count is written in our number system as a series of numbers with periods in between them For example: 220.127.116.11.0 means 8 baktuns, 0 katuns, 0 tuns, 0 uinals and 0 kin. 18.104.22.168 is 1 katuns, 3 tuns, 3 uinals and 7 kins.
Long Count in Terms of Inscriptions
The Long Count was used at the beginning of inscriptions. Dates introducing inscriptions went like this: first came an introductory glyph that was larger than the other glyphs. In the middle of this glyph was a glyph of the patron god of the Haab month in which the Long Count date took place.
Then came the Long Count date, after which came the Tzolkin date. Following the Tzolkin date was a glyph possibly depicting a Lord of the Night, then a glyph that could be a title of the Lord of the Night and 6 glyphs on the moon date in connection to the Long Count date. Finishing up this long date sequence was the Haab date.
The ancient Maya believed that the current world began on the last day of the last baktun: 22.214.171.124.0, a date on which 4 Ahau of the Tzolkin and 8 Cumku of the Haab fell. People have tried to figure out when this was, and the most commonly accepted date is 11, 12, or 13 August 3114 BC. A common projection for the finishing of the current baktun is December 21, 2012.
In the Maya culture, the completion of a baktun was a significant event -- the completion of a “great cycle”. It may have even been a time to celebrate for the people who saw it completed. In this way it is like how the year 2000 was for us.
**In Classic Mayan writings, either word was used. However, more often they used uinic. In Colonial times, writers used uinal more.
“A Forest of Kings”; Linda Schele, David Friedel; 1990
Southern Polytechnic State University: Mayan Myths -- Mayan Calendar
“The Ancient Maya”; Robert J. Sharer, Loa P. Traxler; 2006