These miraculous inventions show the ingenuity of the Mesoamericans.
From early on, they had worked out a solar year of 365 days made up of eighteen twenty day months and five nameless days. Each of these months was associated with a particular god and activities and festivals were organised around the god's predilections.
The five nameless days were considered very unlucky and little activity occurred during these. Since there were no leap years, some kind of correction must have been in place however the details of this have been lost to antiquity.
This 365 day cycle also ran concurrently with a 260 day calendar that bore no relation to the sun or stars and is shrouded in mystery.
These fascinating calendars are carefully hand crafted by skilled artisans in Jalisco, Mexico and make wonderful and mysterious wall decorations.