Well, let's see, while 400 is an integral factor of 1000, it is of 2000, so 5 of these 13*400 = 5200 year cycles is indeed 26,000 years. 400 years is just ballpark, and if Sam5's 394 years is correct, this would be 5*13*394 = 25,610 years.

Wiki gives the precessional cycle as 25,765 years, but the precessional speed is actually a variable, and I think is slightly increasing.

So is this evidence that the precession was indeed encoded in the Mayan calendar?

-Richard