Ha, ha, it is a good one.
Not to be picky, but this is a good excuse for more trompo talk. The Aztec calendar is related to the Mayan calendar, which is the one supposedly expiring. The Cometa Azteca is a copy of the 5 Estrellas Azteca, which also at one time had a Maya top:
The Azteca has in fact their calendar:
while the Maya had a god (I think it is a feathered serpent related to the Aztec Quetzalcoaltl):
By the way, I researched Wikipedia for this, and found this interesting fact about the end of the Mayan calendar:
"Misinterpretation of the Mesoamerican Long Count calendar is the basis for a popular belief that a cataclysm will take place on December 21, 2012. It is simply the day that the calendar will go to the next b'ak'tun, at Long Count 13.0.0.0.0. The date on which the calendar will go to the next piktun (a complete series of 20 b'ak'tuns), at Long Count 1.0.0.0.0.0, will be on October 13, 4772. Sandra Noble, executive director of the Mesoamerican research organization Foundation for the Advancement of Mesoamerican Studies, Inc. (FAMSI), notes that for the ancient Maya, it was a huge celebration to make it to the end of a whole cycle".