last couple of links:
The Sky Isn't Falling, But Pieces Sure Are
By Robert Roy Britt
Senior Science Writer
posted: 11:35 am ET
01 October 2003
http://www.space.com/scienceastronomy/chicken_little_031001.html
Chac 1.1.1
by Warren Anderson
a Mac program that generates Mayan calendar graphics
http://hyperarchive.lcs.mit.edu/HyperArchive/Archive/app/time/chac-111.hqx
"Chac is a mesoamerican calendar for the Macintosh... A prodigious quantity of complete [rubbish] has been published in books and especially on the internet about the calendar. Be careful what you read and believe. You can come to any conclusion you want when you do crappy research, falsify and misinterpret the evidence. Be a skeptic. Research this subject before you contact me with complaints about the way this program does the calculations. I do have a life outside of this program... Mesoamericans did calculations far into the past and future. This program only does them for thirteen baktuns. This is what the Mexicans refered to as the Fifth Sun. It started on September 6th, -3113 using the G.M.T. correlation. This is probably the most mis-stated date written about in books about the Maya. If you don't believe me, do the calculations yourself. The last day of the Fifth Sun is December 20th, 2012."
[note: the book "Lost Languages" places the beginning date on Aug 13 3114 BC, and the end date on Dec 23 2012; it could be that one or both were unaware of the vanishing days stemming from the Julian to Gregorian correction during the 17th through 20th century (depending on the country); chances are neither has read the FR topic about the problems with retrocalculated eclipses]
Impact probability has been revised to zero, using the longer baseline from "found" images.
The Mayan calendar has a "sun" (currently the fifth sun) which lasts more than 5000 years. The Venusian cycle is just one thing they kept track of. The main basis of their calendar was a 260 day period, along with a 365 day (ordinary solar year, pretty much) period.
Professor Says Mayan Calendar Does Not Portend Earth's Doom (2012AD)
http://www.freerepublic.com/focus/f-news/815326/posts
see also the "in reply to" link from this message. :')