Graancirkels

The new Silbury crop-picture takes 'crop messages' to a new level! Anyone can see that it encodes some kind of important message, relevant to ancient Mayan-Aztec prophecy.

So I spent several days learning Mayan-Aztec calendar systems, and now believe that the interpretation is unique and straightforward. It seems to be just a large "calendar clock", with time shown in four different units (analogous to days, hours, minutes or seconds) along the outside, plus a 'moving clock mechanism' in the center.

Both 'inner hands' tell us that we lie precisely (52 / 6) = 8.67 years from the end of the 'Fourth Sun' in 2012.9, where 2004.6 (August) + 8.67 = 2012.9 (almost). The same picture would have had to be drawn in February 2004.2 to be perfectly accurate (no crops were growing then).

Aztecs and Mayans used three different calendar systems with 260, 360 or 365 days per year, but the crop-artist for simplicity drew everything in 360-day 'years'.

Outer dial of the clock: 4 shaded areas represent 5200 years each, and symbolize four previous or current "Suns", just as for the Calendar Stone in Mexico.
10 outer boxes per Sun (over any 90 degree quadrant, with boxes 1 and 2 always shaded) represent 520 years each.
10 inner boxes per Sun (again over any 90 degree quadrant) represent 52 years each (the most fundamental Mayan unit of time covered 52 years, as the convergence of 365 and 260-day calendars).
Finally, because we lie so close to 2012.9, the crop-artist added a feature not present in Mayan-Aztec culture: he/she divided the two inner-boxes closest to any shaded region into finer divisions of (52 / 6) = 8.67 years, by means of (2 x 3) =6 fine-lines.

Now both "hands of the clock" point precisely to the last fine line before any shaded region, meaning that we lie today "8.67 years from the end of the Fourth Sun".

Inner hands of the clock: two 'bundles' of 20 fine lines tell us that we are working in Mayan-Aztec mathematics. For most historical dates or 'long count', the Mayans or Aztecs used powers of 20: for example 20 days per month, 20 years, 20 x 20 years, 20 x 20 x 20 years.
Thus within any 'Sun' of 5200 years (as shown four times on the outer dial), we find 13 x 20 x 20 = 5200 years calculated in another way, and sometimes represented as 13.0.0.
Looking again at the inner hands, we see however only (2 x 6) = 12 thick curves above and below: signifying 12.0.0, and indicating that 13.0.0 is near.

Summary: Two different Mayan-Aztec calendar schemes are encoded in the diagram, leaving no possibility for error.
The outer dial counts time as 52 x 10 x 10 =5200, and uses a set of six fine lines near any shaded area for greater accuracy, namely 52 / 6 = 8.67.
The inner hands count time as 12 x 20 x 20 or 12.0.0, since 13 x 20 x 20 = 13.0.0 = 5200 has not yet been reached.
Because the information provided in both parts is redundant, we can be sure that the interpretation is correct. In other words, "the end of the Fourth Sun is near and on schedule". An incredibly clever scheme of pictorial mathematics.