The Mayan Calendar

The Mayan Calendar system is the greatest technological advance of the ancient Maya. It is a sacred process recording time. Time was very important, associated with manifestation of gods and the creation of the universe.
This sophisticated way of time keeping allowed the Maya to record important events such as births and deaths, times when rulers took and lost power. This ancestral Knowledge guided the Mayan existence since birth. The Calendar Round is made up of two calendars - the Tzolkin, and the Haab.

Numbers:

The Maya were the only ancient culture to make use of the concept of zero in their mathematical and calendrical system. It was represented by the image of a shell. Their numerical system was based on the number 20, known as a vigesimal system. Numbers were expressed in the written form using dots to represent units of one and a line as a five.

After four dots are reached, the line is used to symbolize five and further dots are added above to make six, seven, eight and nine, until two lines make up ten, and so on. Twenty is represented with a shell with a dot above it.

A number can be given a different value depending on it's position. Numbers increased by 20-fold when they are moved from a lower position to a higher position. The first 20 numbers in Maya are Written as follows:

The Dresden Codex has been an important document for the decoding process of the Long Count Calendar as it contains accurate astronomical information about solar and lunar eclipses, and the cycles of Venus and Mars.