Someone seems to doubt the swastika below is an Aztec calendar so I include an excerpt from the website I got it from.
We find here the Aztecan calendar cycle of 52 uncorrected years represented in the form of a left rotating "swastika". The wheel starts with the year 1 Acatl, then turns left to 2 Tecpatl, 3 Calli, 4 Tochtli, 5 Acatl, etc. There is a good explanation of the whole composition in Duran and Seler. The question is, did the Hopi have a real writing system like the Aztecs and did they share the same calendar around the year 1000? Why do they not have a developed writing in the 17th century?
ABOUT SWASTIKA - Esoteric Online