Earliest evidence for Maya calendar may have been found in Guatemala

The earliest evidence of calendar use by the Maya may have been found in the remains of an ancient temple in Guatemala

By Carissa Wong

Two pieces of an ancient wall may preserve the earliest evidence of the Maya calendar. The fragments are decorated with a dot and line above a deer head – representing one of the dates from the 260-day calendar – and they are from a temple built between 2300 and 2200 years ago in what is now Guatemala in central America.

Several ancient communities living across the Americas – including the Aztecs, Maya, Mixtecs and Zapotecs – tracked the time using cycles of 13 days denoted by numbers, alongside cycles of 20 days named after gods. In this calendar, a specific day is assigned both a number and a name, producing 260 unique days before the cycle repeats. It is thought that people used the calendar to decide when to hold ceremonies, to mark important dates or to attempt to predict future events.

Until now, most previous early evidence for calendar use by these ancient people had been found on stone monuments dating to around 100 BC. David Stuart at the University of Texas at Austin and his colleagues have now found evidence that the Maya people may have used this calendar over a century earlier.

The team previously discovered the San Bartolo archaeological site, which includes a pyramid called Las Pinturas – meaning “the paintings” – back in 2001. Excavations then revealed that the Maya completed several phases of construction, with earlier structures eventually knocked down to form the foundations of the pyramid.

When the researchers were sorting through pieces of plaster collected from the pyramid’s foundations, they realised that two pieces fit perfectly together to form a date symbol.

“That was a stunner – we believe that this is the earliest example of the use of the Maya calendar, showing the day seven Deer,” says Stuart.

The fragments came from the remains of a long platform that was probably built to track astronomical events as well as the time. “This platform may have acted as an observatory for looking at the rising sun or other astronomical bodies in the sky, or for just keeping track of time. Like a kind of architectural clock,” says Stuart.

By radiocarbon dating charcoal found alongside the fragments, the team dated the symbols to between 300 and 200 BC. Stuart believes the symbols may have been used to denote the date of a new year, but they may also have been used to reference a person or deity.

However, some archaeologists question whether this is really the earliest evidence of the 260-day calendar. Mary Pohl at Florida State University believes that a previously discovered roller stamp from Tabasco in Mexico shows this date notation was used in 500 BC. But Stuart thinks the symbols on the stamp from 500 BC aren’t necessarily a form of date notation comparable to the Maya system.

“Early evidence of the… calendar has been debated, but in this study they present clear evidence of the 260-day calendar use. This is very important work,” says Takeshi Inomata at the University of Arizona.

Journal reference: Science Advances, DOI: 10.1126/sciadv.abl9290

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