Cycle turn dates are derived from what is known as the Bradley Sideograph... If you are not familiar with this indicator you can go here for an explanation of the Bradley: http://www.amanita.at/e/faq/e-bradley.htm
Blue moon this Saturday... Seems like it could be an influential event especially considering that it intersects the same time interval as a proposed turn date. I have not been following moon phases, but I think I probably should start. Thanks for the link Bull...