Plate 27 showing 365 days in each of the first four solar years of 52 year cycle.

( revised 29 April 2008)

(Click to enlarge image)

This plate illustrates the first four leap years as they are counted in the ritual calendar with a modification to synchronize with the agricultural cycles.

The bottom right section shows the start of a leap year at 1 Cipactli. The next five quadricenas include 260 days ending at 1 Coatl. Two more quadricenas, 104 days, end at 1 Reed. Seven rows of quadricenas have been counted making an elapsed count of 364 days

At this point the early astronomers inserted another day to corrrespond with the solar year, to continue at 1 Mizquitli as demonstrated on Plate 27 in the upper right quadrant. Many years must have expired to allow an observation that seven ritual years needed another day to keep the cycles synchronized.

A new starting point is established in column 2 and a new number 1 is assigned to 1 Mizquitli to start the second year. The next cycle of 7 quadricenas ends at 1 Tecpatl. Another day is added and the new begins at 1 Ozomatli. This solar year ends in similar fashion at 1 Calli.

An added day starts the next solar year at 1 Tochtli. and ends at 1 Cozcacauhtli.

Remember that 10 Movement indicated an endless repetition of day names.

This pattern continues until the completion of a 52 year cycle with a new appearance of 1 Cipactli. 365 icons have been counted in 52 years, yielding a total numbers of days 365x52=18980. This is only missing 13 leapyear days in the modern count of one extra day each 4 years that are called leap years.

The appearance of water in the paintings each of the four year quadrants is an indication that these were agricultural years. Some of the repetitions of a ritual calendar would not have equal likelihood of water and would not be expected to provide equal water supply. This indicates a sort of divination which can be read from Codex Borgia but there is no indication of which year will have water.

Interpretation of this painting:

A cycle of 52 years is completed in 18980 days which is only missing the 13 days added by leap years in the calendar used in modern times. It is probable that continued observation of agricltural cycles would have prompted the early Mexican astronomers to add another day every four cycles of seven quadricenas, every 32 quadricenas.