Weren't the Mayans very interested in astronomy - isn't there is a galactic alignment in 2012, maybe this is why the Mayan calendar ends at this date, stepping from one age to another. It could be as simple as that.
Maybe I am way off the mark.
Yes, they were also very interested in cycles beyond just moving from one age to another. This is very evident simply in their ritual, and I am working off the top of my head hear and can't remember the specifics, where every certain period of time, they buried all their possessions and started fresh. In speaking to many Mayans while I was in Mexico, it seems logical that the calendar was astrological and like much of their culture, involved the cycles of the nature and planetary objects. At key times during these cycles they had rituals, ceremonies and practices to mark, revere and basically stay attune to these times, cycles and patterns and the mythology that surrounded them. This is what was told to me by those I spoke to anyway. Keep in mind, they weren't the actual wisemen/priests though, mostly just tour guides and villagers.
The basic belief of the Mayans involved the cycle of day to night and back through to day. And, of course the cycle of the planetary objects was another larger cycle. The night was a time for renewal and application while the day was when these things were brought to light, and the benefits/penalties of the nights activities were experienced. Surrounding that, were larger cycles where similar identifications and beliefs were patterned. Obviously, it's too much to go into in one post, but there is a lot of reasonable interpretations online that actually stem from what the Mayans actually believed, as told by Mayans themselves.
Who knows though, maybe all these guys speaking for the Mayans without really ever asking any actual Mayans on it are right... maybe the Mayans are just keeping this end of the world thing to themselves because we aren't worthy of the knowledge. Ha! I kid, I kid...
I've often wondered that if the calendar DOES in fact end at the exact cosmic alignment that it appears to possibly end at then perhaps the calendar simply is then meant to be read backwards. Then when you hit the "start" again, you simply reverse the order yet again. In other words, you cycle through the calendar just as the alignment would no doubt follow a cyclical pattern as well. Of course, that is nothing more than personal speculation and I don't really know TOO much about the whole cosmic alignment that they speak of... where the earth is in the exact galactic centre or whatever...
