The Aztec Calendar or Sun Stone?

The commonly called Aztec Calendar is a basalt monolithic sculpture is about the Aztec cosmogony and its sun cults. Is also a representation of Tonatiuh, the Aztec god of the sun, around him are engraved the symbols of the days, this is why it is called calendar. The original version is currently on display at the National Museum of Anthropology in Mexico City.
This piece has been point of debate because how it is called. As I mention before commonly it is called Aztec Calendar, because it have engraved the symbols of the days. But many people think that if it has engraved the symbols of day but it is not a piece designed to tell the date. This people said that the “Aztec Calendar” is really a not finish altar used for sacrifice.
What do you think? I prefer to believe that it is a not finish altar used for sacrifice. It is known that the Aztecs and others Mesoamericans cultures put in a high level the sacrifice in their cultures. And this not because they like to kill, they always have a meaning behind. They think that when they sacrifice someone they can prevent the madness of the gods or also they can invoke the kindness of the gods. I prefer called it Sun stone because it has a much strong meaning. And this represent what the Aztec culture was, full of double significance.