2012 is it. The year the Oreo turns 100 years old. The Mayans must've known this, hence the reason their calendar predicts its shape. To celebrate, Nabisco should make a Mayan calendar Oreo for mass consumption and bury a few in strange pyramid-shaped boxes somewhere in a jungle...

The Stone Of The Fifth Sun is Aztec, but i know what you mean. Also, they counted in vigesimal, so a hundredth anniversary wouldn't be so significant to them.

I kind of figure they thought that there wasn't much point
in calculating it more than a couple thousand years in
advance and planned to update it as needed.

There are inscriptions mentioning dates thousands of years after
today and many powers of twenty above the few millenia
covered by the bottom few places of the Long Count. I seem to
remember it's twenty-odd aeons long altogether.

//That IS summer, mate// in the southern hemisphere, where, by a bizarre coincidence, the Mayans (and the Aztecs) lived. In particular, it's close to the summer solstice.