Maya calendar - Wikipedia, the free encyclopedia

Maya calendar - Wikipedia, the free encyclopedia: The Maya calendar is a system of calendars used in pre-Columbian Mesoamerica, and in many modern communities in highland Guatemala and in Mexico. and in Chiapas.
The essentials of the Maya calendric system are based upon a system which had been in common use throughout the region, dating back to at least the 5th century BCE. It shares many aspects with calendars employed by other earlier Mesoamerican civilizations, such as the Zapotec and Olmec, and contemporary or later ones such as the Mixtec and Aztec calendars. Although the Mesoamerican calendar did not originate with the Maya, their subsequent extensions and refinements of it were the most sophisticated. Along with those of the Aztecs, the Maya calendars are the best-documented and most completely understood.

A different 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 is the Long Count. It is a count of days since a mythological starting-point.[5] According to the correlation between the Long Count and Western calendars accepted by the great majority of Maya researchers (known as the Goodman-Martinez-Thompson, or GMT, correlation), this starting-point is equivalent to August 11, 3114 BCE in the proleptic Gregorian calendar or 6 September in the Julian calendar (−3113 astronomical). The GMT correlation was chosen by John Eric Sydney Thompson in 1935 on the basis of earlier correlations by Joseph Goodman in 1905 (August 11), Juan Martínez Hernández in 1926 (August 12), and Thompson himself in 1927 (August 13).[6][7] By its linear nature, the Long Count was capable of being extended to refer to any date far into the past or future. This calendar involved the use of a positional notation system, in which each position signified an increasing multiple of the number of days. The Maya numeral system was essentially vigesimal (i.e., base-20), and each unit of a given position represented 20 times the unit of the position which preceded it. An important exception was made for the second-order place value, which instead represented 18 × 20, or 360 days, more closely approximating the solar year than would 20 × 20 = 400 days. It should be noted however that the cycles of the Long Count are independent of the solar year.

The exact origin of the Tzolk'in is not known, but there are several theories.

One theory is that the calendar came from mathematical operations based on the numbers thirteen and twenty, which were important numbers to the Maya. The numbers multiplied together equal 260.

Another theory is that the 260-day period came from the length of human pregnancy. This is close to the average number of days between the first missed menstrual period and birth, unlike Naegele's rule which is 40 weeks (280 days) between the last menstrual period and birth. It is postulated that midwives originally developed the calendar to predict babies' expected birth dates. The deity Ix Chel is thus of particular interest due to her mythic relation to the calendar.

A third theory comes from understanding of astronomy, geography and archaeology. The mesoamerican calendar probably originated with the Olmecs, and a settlement existed at Izapa, in southeast Chiapas Mexico, before 1200 BC. There, at a latitude of about 15° N, the Sun passes through zenith twice a year, and there are 260 days between zenithal passages, and gnomons (used generally for observing the path of the Sun and in particular zenithal passages), were found at this and other sites. The sacred almanac may well have been set in motion on August 13, 1359 BC, in Izapa. Vincent H. Malmström, a geographer who suggested this location and date, outlines his reasons (while offering strong arguments against both of the former explanations):

(1) Astronomically, it lay at the only latitude in North America where a 260-day interval (the length of the "strange" sacred almanac used throughout the region in pre-Columbian times) can be measured between vertical sun positions–an interval which happens to begin on the 13th of August–the day the peoples of the Mesoamerica believed that the present world was created;

(2) Historically, it was the only site at this latitude which was old enough to have been the cradle of the sacred almanac, which at that time (1973) was thought to date to the 4th or 5th centuries BCE; and

(3) Geographically, it was the only site along the required parallel of latitude that lay in a tropical lowland ecological niche where such creatures as alligators, monkeys, and iguanas were native–all of which were used as day-names in the sacred almanac.

A fourth theory is that the calendar is based on the crops. From planting to harvest is approximately 260 days.