Through most of its 26,000-year history, homo sapiens have followed the moon and used moon calendars. The moon is fickle and erratic. It is of nature, subtle and elusive. By current reckoning, it turns on its axis every 29.5 days, the length of a synodic lunation, which is why we always only see one side of the moon.
A synodic lunation of 29.5 days, the duration of one moon cycle seen from the Earth, is only one of the lunation cycles from which lunar compilations can be made. There is also the sidereal lunation cycle of 27.33 days (the time it takes for the moon to return to a fixed point in the sky); the 27.32 tropical cycle (taken from the celestial longitude), and the draconic cycle of 27.2 days (the time it takes the moon to return to the same node).
Right up to the 20th century, pre-agricultural humans, such as the Lakota, have followed a vague or unfixed moon calendar. The fact is that during one solar year there is always a 13th lunation which transits from one solar year to the next. The taboo nature of the number 13 seems to stem from the mysterious 13th moon. There is an 11-day discrepancy between the length of the solar year of 365.242199 days and 12 complete synodic lunations of 354.36706 days. The number of days in 13 synodic lunations amounts to 383.5, a discrepancy of 18.25 days more than the solar year.
The discrepancy between days of the solar year and lunation cycles only became a problem for civilized man, for woman has always naturally carried the 13 moons within her being. The female menstruation cycle of 28 days is the mean between the synodic lunation cycle of 29.5 days and the other lunation cycles of less than 27.5 days. Factor the mean lunation cycle of 28 days into the solar year and the result is 13 moons, or 364 days, one day less than a mean solar year.
Once agricultural lifestyles were developed in the area of the planet now known as the Middle East, the male priesthood seized power. The question of a calendar became a matter of developing an instrument of power. The male power became associated with the sun, while the female was associated with the moon. A calendar based on the exclusivity of the solar year became paramount. The Egyptian division of the circle into 360 degrees, subdivided into 12 parts of 30 degrees each, provided the male priesthood of Egypt and Mesopotamia with the norm for their celestially oriented "male solar" hierarchies. This occurred some 5,000 years ago, ca. 3000 BC.
Thus, in Babylonia and Egypt were born the 12 houses of the zodiac (and traditional Western astrology) and the 12-month calendar. Since 12 months of 30 days yield only 360 days, an extra five-day purification period was added on to complete the solar year. The chief function of the Babylonian priests of the calends was to correlate the cycles of the moon with the solar year. By 1500 BC, the system of the 360 degrees of the circle divided into 12 as an approximation of or even as a replacement for the lunation cycles spread to India and China. The 12 is based on the division of space - a circle; not time - the 13 moons.
From Babylonia and Egypt the "solar power" of the circle of 12 spread to Greece, and thence to Rome. It was Priscius Tarquinus, early emperor of Rome (616-579 BC) who is credited with the development of the calendar from which the Gregorian is ultimately derived. The names of the Gregorian months are all Latin and come from this early Roman calendar.
By the time of the rise of the Christian Church, AD 500-1000, the Roman calendar of 12 months of uneven days in disregard of the lunation cycles was an established fact. At the beginning of the Age of Conquest, AD 1500, it was known as the Julian calendar and was based on the synodic year of 365.25 days. The Gregorian calendar is based on the tropical year of 365.242199 days.
However minute the fractional difference is between the synodic and tropic years, it should not obscure the actuality that the Gregorian calendar is an uneven and illogical distribution of days derived from a male priesthood tradition that stems from Babylonian civilization. It is a tradition of time-reckoning based on the Egyptian division of the circle, which is a division of space and not time, and in which all taboos of the number 13 are fully incorporated.
It is precisely this power of 13, associated with witchcraft and the devil, that the conquering Europeans confronted head-on when they arrived in the"New World". For here was a tradition of time and knowledge even more precise and fully developed than in Europe, completely based on the 13. We are referring here to the calendrical and mathematical system of the Maya upon which all Mesoamerican (Mexico and Central America) civilization was based.
There was no chance of real dialogue where the Christian priests and their zealous soldiers were concerned. People of learning were put to death, and libraries burned. The world was deprived of an understanding of time that was based not on the spatial divisions of the circle but on the lunar-galactic power of 13.
Of course, because of the hypnotic spell of the Gregorian calendar - the Dreamspell of History - you will not find a discussion on the Mayan understanding of time in the Encyclopaedia Britannica entry on calendars. That is the Mayan Factor, the overlooked factor in any accounting of human affairs. Yet if we remain only in the spell of the Gregorian calendar and ignore the Mayan Factor then truly we are lost.
The Mayan timing frequency is 13:20 and not 12:60. Thirteen refers to the 13 galactic tones or powers of creation, which are also encoded in the 13 moons or annual lunations. Twenty refers to the 20 solar frequencies encoded as the 20 icons or solar seals. Upon this timing frequency was based the tzolkin or 260-kin 'sacred calendar'. Combined with the solar cycle of 365 days, the tzolkin gave the Maya the fractal yardstick by which they could construct calendars and timing systems that demonstrate the harmonic order of the solar system and galaxy in general. Within these constructs, the Maya also maintained their lunar calendars and eclipse cycles of utmost precision.
Because the basis of the Mayan calendar was the 260-kin tzolkin and not the 360 degree circle, there was not need to correlate the lunation cycle to the solar year through the abstract concept of "months!". The Mayan mathematic, based on an elegant and more sophisticated dot-bar notation system, is vigesimal not decimal - that is, based on 20s rather than 10s. This gives the Mayan mathematical system a fractal and exponential flexibility not exhibited by the decimal or duodecimal (by 12s) system upon which the Gregorian calendar is based.
Instead of months, the Mayan solar year is divided into eighteen 20-day periods called vinals. In actuality the 18 vinals, plus the five-day vayeb, were a means of correlating the solar year to the 13:20-based Tzolkin.
Long a puzzle to Western archaeologists, who early on understood its amazing sophistication and complexity, the Mayan calendar and mathematics have nonetheless been regarded as an anomalous curiosity, with no application to the modern world. Again, this prejudice must be seen as a function of the 12:60 consensus reality.
The fact of the matter is that the Mayan calendar contains the teaching of fourth-dimensional time that has eluded modern science, immersed as it is in the unexamined grip of third-dimensional Gregorian time. The nub of the Mayan teaching is the application of the 13:20 frequency to the creation and implementation of the calendar of the 13 moons."
Excerpt from the Call of Pacal Votan by José Argüelles