260 or 256 years? It can be both!
This, apparently, is the riff I’m on as theAbysmal blog is in its last few days. Looking at history in cycles of 260 years, which to the Maya worked out to 256 years 98 Days using their Long Count Calendar. theAbysmal Calendar has a Leap Year Day every 4 years (hint: this year it’s December 19th 2016), and an exception every 128 years when we don’t have the Leap Year Day. This keeps theAbysmal Calendar Year better aligned to the Tropical Year and so the seasons. Two of these exception periods work out to 256 years. Measuring history in 256-year cycles is a way to embed the Leap Year Rule into longer measures of theAbysmal Calendar, and it approximates the Maya cycle as well (falling out of synch by a quarter year every cycle).
Although the 128-Year Leap Year Exception is a function of theAbysmal Calendar, the 260-Year Cycle developed out of the Maya cyclical view of history. It seemed most appropriate to use a calendar developed and used in what was to become the world’s first global city, Mexico City. So, in looking at 260-Year periods of history, most notably the one that has just ended, 1752 to 2012, representing the Industrial Revolution. 260 is a product of two key numbers in timekeeping, 13 and 20. Breaking the 260-Years into 13 periods of 20 Years makes it a little easier to manage in terms of periods, but could just as easily be divided into 20 periods of 13 years. At least with 13 years, we can look at the 20-Year period at the apex (i.e. the central part of the historical cycle). This is 1872-1892 CE.