Their observations were recorded in hieroglyphic books, in which they developed tables for predictions. Three books – The Dresden, Paris, and Madrid codices – contain such tables, with the explanations and specific applications.
From circa 300 AD to 900 AD the Mayan civilization flourished in Guatemala, El Salvador and the Yucatan Peninsula of Mexico producing marvels of architecture and indubitably one of the world’s most puzzling systems of writing.
The enigmatic writing system is so different from any other in human history that it will certainly require cryptanalytic techniques to make plain text out of the Maya mélange of double-duty ideographs, rebuses and phonograms.
The circle is basic to their religion and philosophy of life. It is the basic to their calendars and tables of celestial events. They viewed the universe and all within it as an unending and expanding circle of time and space.
The Mayan astronomers-priests, in their obsession with time, showed an uncanny ability to play their calendars against one another to achieve extraordinary accuracy through a system of mutual correction and to arrive at common “resting places” when two or more celestial events would coincide.
All was recorded in their hieroglyphic books, in which they developed tables for prediction.
The document ‘The Maya Astronomical Computer ‘was classified as 'top secret' but is now disclosed.
Here is the link to the NSA document: The Maya Astronomical Computer
Source: cryptome.org, niburu.nl