Mesoamerican astrology seems to be of little interest to the astrological community, probably because it is different and in a state of reconstruction and requires real insight, not just learning from other people's delineations. While there is a horoscopic form that I've proposed and worked on, calculations present some difficulties and currently only one piece of software does it, and in rather a cumbersome way. It does seem to be of much interest to people outside the astrological community, however, but these people are interested in it as a kind of divination or a gateway to the end of the world in 2012. I've got a lot of articles about it on my website www.onereed.com
for those who may be interested.
That being said, the topics I mentioned in the first post I think are important and it would be good to get some consensus on a few things like - what exactly are the day-signs, how do they work and when does the day begin for this system? They seem to me (and seem is the best that I or anyone else can say about them as no real studies have been done except for a little one I did many years ago) to be a kind of biorhythm that counts to 20 then starts again. Beginning with the premise that the observations of myself and others confirm the delineations that I've developed and that these day-signs actually work as well as Western astrological signs, my guess is that there is some kind of light-counting cellular function and that this is a means of generating some variation on the individual level. I actually think that's what astrology is really all about - generating minor variations among members of a species which play a short-term role in the process of natural selection.
So what is a day-sign is a great question. The best way to go about answering this question is to first figure out what your day-sign is, and those of others you know, and try to make some sense of it. People trained in astrology will be at an advantage and some have confirmed by observation that the day-sign appears to synthesize the solar and ascendant features of the natal chart - and even dominant planets.