Mayan Calendars #

There are at least three Mayan calendars. I was listening to the How Stuff Works: Mayan Calendar podcast, and learned that the Mayan calendars are not as strange as I expected them to be. Let’s first look at how our years are structured:


When the last component overflows (from 9 to 0), we carry one and increment the decade. When the decade overflows we increment the century. This is how base 10 numbers work.

Now let’s look at how dates are structured:


When the last component (day) overflows from 31 to 1, we carry one and increment the month. When the month overflows from Dec to Jan, we increment the year. This is very similar to how base 10 numbers work, except that each component has its own rules for when it overflows, and months don’t all have the same number of days.

How are weekdays numbered? We can say both the day of week and the day of month, and increment both each day:

the 23rd
day of month

The Mayan Tzolk’in calendar works like this. Both components are incremented each time. One component has 20 days and the other has 13 days, and they line up every 260 days.

day name

The Mayan Haab calendar is more conventional, lasting 365 days. There are 18 months each with 20 days, giving 360 days, plus an extra 5 days to make it fill a year. They didn’t handle leap years.


The Mayan Long Count calendar is the one people are worked up over. There are five (or maybe nine) “digits”, each base 20 except one that’s base 18 to match the months of the Haab calendar. However the Long Count calendar doesn’t include the extra 5 days, so it doesn’t stay lined up with Haab.

tun (year)
uinal (month)
kin (day)

What’s the big deal about 21 Dec 2012? It’s, at least under the most common translation of our calendar to the Mayan calendar. It’s sort of like how people celebrated the year 2 0 0 0. It’s nice to celebrate a bunch of zeros. Some interpretations say that it doesn’t go to but resets back to, but it’s not universally agreed upon, and some say that there are four more places in the calendar system, so it’d be, resetting only after 63 million years.

In any case, the thing I find strangest about the Mayan calendar systems is that there are so many of them, somewhat incompatible with each other. In addition to the three I described above, there’s a 9 day cycle, a lunar cycle, a Venus cycle, and a few others. See the Wikipedia page for a reasonable overview. If you use Emacs, the Mayan calendar is included, and you can use M-: (calendar-mayan-date-string) to get back a string like "Long count =; tzolkin = 12 Men; haab = 18 Mac".

Appendix: dates

There are different translations between Mayan dates and our dates. A lot of this has to be reconstructed because Christians burned the Mayan books. I translated the Wikipedia list of date translations into a list of dates for

Correlation name13.
Modified Spinden1753-02-22
Modified Thompson 12012-12-22
Thompson (Lounsbury)2012-12-23
Böhm & Böhm2116-12-14
Fuls, et al.2220-11-06

Emacs: Helm for finding files #

When using Emacs I’m often switching buffers or opening files, so I’m always on the lookout for ways to make those operations more pleasant.

A while ago I tried Anything.el. Anything is like Quicksilver for Emacs. It’s powerful but I found it confusing to set up. Emacs-Fu had a blog post about configuring anything.el, and I used that for my setup.

For the most part, I use it instead of find-file:

screenshot of helm-for-files


Unstructured to Structured #

I find that I often don’t know a structure or abstraction until I’ve worked with something more concrete. This happens in programming but it also happens when creating structured information.

While helping Wild Shadow Studios with Realm of the Mad God, we held our discussions in Google Wave for two years, until Google shut it down. Why did we use a tool everyone else thought was useless?

  • Group Chat: The 3–6 of us could chat about the game.
  • Asynchronous: We could continue conversations while not all of us were online.
  • Nesting: We could reply to individual points made in another message.
  • Attachments: We shared test binaries or screenshots.

It was nice for keeping everyone “on the same page”.

Wave didn’t work well for us when it came to adding structure. We had thousands of chat messages in the system, but when a bug or feature or idea came up, there wasn’t an easy way to transition into a task tracker. As a result, those kinds of things were too easily forgotten.

When I use tools like Asana or Trello or Cohuman, they want me to start with structured data, but they don’t handle the informal unstructured nature of IM or Wave. Where do those tasks come from? They came from somewhere, but that history isn’t preserved when you create a new task in a task tracking tool.

I want a tool that lets me hold unstructured conversations, then extract portions of conversations that led to a task, and move them into my task tracking tool. Unstructured comes first for me; structure is what I add later, once I understand what structure I want. Databases and most structured tools I use get this wrong — they ask me to decide the structure first. Spreadsheets, Wikis, Wave, and most unstructured tools also get this wrong — they let me easily work without structure, but don’t offer me a transition to something structured. JotSpot, before it was bought by Google, is the only tool I tried that had a smooth transition from unstructured to structured.

It’s also possible I’m cursed to like things that have a lot of potential, but can’t be understood in five minutes, and thus are doomed to niche status. I think Wave and JotSpot both fit into this category.