The ancient Mesoamerican culture apparently used a 260-day calendar. This finding is certainly unique, because the Gregorian calendar that we use today, calculates the length of one year consisting of 365 days.
Uniquely, the calendar used by the Mayans is somewhat complicated based on knowledge of the Solar System, which is much earlier than previously realized.
Quoted from IFL Science, the researchers found the use of this sophisticated calendar system by looking at the astronomical orientation of hundreds of structures found used in various ceremonies by the ancient Mesoamericans.
In one study, archaeologists looked at data from aerial LiDAR laser scans that can 'peep' deep beneath densely populated Central America to reveal the presence of long-lost structures.
Among the 33,935 architectural complexes they screened, 478 were ceremonial complexes belonging to the ancient Olmec and Mayan civilizations who lived between 1100 BC and 250 AD.
This was a time when the Mesoamerican civilization was still small. People began to shift from a nomadic hunting and gathering lifestyle to a sedentary lifestyle triggered by the rise of corn farming at that time.
Most ceremonial complexes were rectangular in shape, featuring flat squares surrounded by rows of mounds, elongated buildings, and pyramids. Like many known Mesoamerican structures, it was meticulously constructed to align with the Sun, Moon, and even the planets of our Solar System.
One of the sites under study was Aguada Fénix, the largest building in Pre-Hispanic history in the Mayan region which is believed to have been used as an astronomical observation platform.
Remarkably, the new research shows that many of the structures are oriented in line with the solstice, quarter day, or lunar cycle of 260 days a year.
For example, a number of structures are positioned according to the sunrise on February 11 and October 29, 260 days apart.
This find is clear evidence that the Mayans had sophisticated knowledge of the stars that dates back to at least 1100 BC. It is also the earliest evidence of a 260 day year calendar.
No one is quite sure why they use today's number in a cycle. But some theorists say this calculation has something to do with some kind of numerological significance, the scheduling of agricultural seasons, even the human gestation period (because 260 days is almost 9 months).
"For the Mayans and other Mesoamerican groups, the numbers 20 and 13, associated with parts of the human body, specific gods, and cosmic levels, were of great importance. Although our data are insufficient to resolve the origin of the 260-day calendar, these findings lead us to support two alternative scenarios, each incorporating numerology and ritual scheduling," the researchers said.
Another interesting note, researchers found that most of the ancient ceremonial structures found are also related to dates in February and March, the peak of the dry season.
This is a period when various activities related to horticulture take a short 'vacation' break to carry out collective rituals, and construction activities.
Perhaps, according to the researchers, the emergence of the 260-day calendar has some sort of connection to the rise of agriculture and the growing cultural understanding of the 'kingdom of space' above us.