67/r (and others) THEORY OF MEANING

[Jorge_Stolfi]

he month is divided in 3 elements as we have been able to see, but it is divided arbitrarily in two equal parts (same thickness) and one smaller part (less thickness)

I think you are mis-interpreting the intentions of the "artist".  The red wedges were quite probably supposed to be equally positioned between the two adjacent "blades" of the "windmill", not part of one of those two blades.  It looks like the latter in some cases, but only because the "artist" was abysmally bad at drawing, including geometric drawing. Perhaps he could divide a circle into four roughly equal parts, but usually his circular sectors are all uneven and the boundary lines miss the center by many millimeters.

the red peaks are the visible menstrual bleeding

Except that menstrual cycles are quite variable, with a mean length of ~28 days.  Not precisely 365/12 = ~30.44 days...

All the best, --stolfi