I've only had a quick look at this so don't take it as a definitive answer. The I-Ching is an ancient Chinese system of fortune-telling. One part of this is a set of 64 symbols known as hexagrams. Each hexagram consists of 6 lines, some continuous, some broken. By arranging these in a particular sequence and noting the numerical differences in the arrangement of the lines between successive hexagrams, a sequence of 384 numbers (384 = 64 x 6) was obtained.
This sequence was then superimposed on a mathematical series to give another list of numbers. Each number was then assigned to a date and the value of that number was said to indicate the particular 'novelty' of that date.
It seems to me that there are two basic flaws in this:
1) The mathematical process is entirely abstract and not related to anything in the natural world.
2) It's necessary to fix a 'zero date' to overlay this graph of novelty on the calendar. You can choose any zero date you find convenient.
So what do we have? A graph of connected points, rising and falling to showing the novelty on any particular date. It's then necessary to look at historical events and try to assign high or low novelty to particularly momentous dates. Terence McKenna (the originator of Timewave Zero) noted a point of low novelty and assigned it to the date of the Hiroshima atomic bomb. 67.29 years after this, the graph reached a zero point, which would have been in November 2012. When McKenna heard of the Mayan Long Count rollover date, he promptly moved his timewave zero plot to make the December 2012 rollover date fit.
So it's a series of numbers generated by an abstract mathematical formula, inherently unconnected to any natural event and open to 'interpretation' (or more accurately 'fiddling') in order to obtain the desired result.
In summary - an interesting variation on numerological nonsense, but nonsense just the same.
Predictive ability = zero.