The internal structure of the calendar, part 2

In December of 2012, I posted a few remarks about the calendar.  The visual representations of the calendar we see in the West usually take the form of a grid in seven columns, each representing a day of the week, with the rows representing the succession of the numbered days of the month as iterations of the sequence of the seven days of the week.  As for example:

What, you've seen one of these before?  That's FANTASTIC!

What occasioned my post in December of 2012 was this xkcd cartoon, in which Randall Munroe wrote the number of each date in a size that reflects the relative frequency with which that date is mentioned in materials searchable through Google NGrams:

In months other than September, the 11th is mentioned substantially less often than any other date.  It's been that way since long before 9/11 and I have no idea why.

The patterns here made me wonder if our usual grid layout oversimplifies the way the calendar is actually structured in our thought and social practice.  I’m a Latin teacher, and so my working life brings me into contact with the calendar of the ancient Romans.  That calendar did not include the week and was not organized as a grid.  Rather, each month had an internal structure in which days were expressed by their proximity to other days and by their religious status.  A visual representation of the Roman calendar might look like this:

This drawing is based on some fragments from about 60 BCE

Recently, other bits have appeared online suggesting that the calendar may have more internal structure than we commonly realize.  This morning on Slate, Ben Blatt looked at times of the year when newborns are most and least likely to be given particular names.  Mr Blatt’s charts, and the box in which readers can search for the seasonal patterns of particular names, are based on death reports released by the US Social Security Administration, since there is no national agency in the USA that collects and publishes comprehensive reports about births.  So his data is about 80 years behind the times, but it still is interesting.

For example, Mr Blatt shows that babies born on prominent saint’s days in the USA 80 years ago were much likelier than other babies to be named after those saints.  So lots of Valentines and Valentinas were born on 14 February, lots of Patricks and Patricias born on 17 March, lots of Johns and Janes born on 24 June, etc.   This strikes me as a bit sad- I’ve always thought the Orthodox had a good idea with celebrating both a birthday and a name day.  Having your birthday and your saint’s day simultaneously would cheat you out of an excuse for a party in your honor.  Mr Blatt also shows that lots of girls named June were born in June, lots of boys named August were born in August, etc.

Last week, Cracked highlighted an old piece called “The 9 Most Statistically Terrifying Days on the Calendar.”  I remember the weaknesses of Cracked magazine, I even remembered them in a post here,  and more than once I’ve seen things on the site that I knew to be false.  So I take everything I read there with a grain of salt.  But each of the items on that listicle looks pretty plausible.  For example, #9 tells us that traffic accidents spike the morning after people set their clocks ahead for daylight savings, since the hour of sleep-deprivation has the same effect as drinking a couple of shots of Scotch.  I haven’t done any checking to verify that or any of the other claims on the list, but none of them is outlandish on its face, and they all have explanations attached that make me feel smart when I read them, so why the hell not repeat them.

 

 

The internal structure of the calendar

The ancient Roman calendar gave special names to two days in each month: the Kalendae (in English, “Calends,”)which was the first day of the month; and the Idus (in English the “Ides,”) which was the fifteenth day of March, May, July, and October, but the thirteenth day of every other month.  Other days were specified by counting the days until the next Calends or Ides.  So, the last day of April was pridie Kalendas Maias, the first day before the Calends of May.  There was some special significance to what came to be called the Nonae (in English the “Nones,”) that is to say, the ninth day before the Ides.  So, in March, May, July, and October, the Nones would fall on the seventh day of the month, and in other months they would fall on the fifth day.  So today, being the fifth, is the Nonae Decembris.   As far as the formal language of law and religion were concerned, this arrangement around the Calends and the Ides constituted the whole internal structure of the month.  The Romans did experiment with various forms of the week, most notably an eight-day week that determined when markets would be held.  Undoubtedly these sequences of days would also have influenced the Romans’ perceptions of time, even if they were not regularly integrated into the official calendar.

I bring this up because of an xkcd strip that appeared a week ago today.  Cartoonist Randall Munroe used Google’s Ngram search to tabulate the number of occurrences of each date by its name (ordinal number + month name) in English-language books since 2000.  In months other than September, the 11th is mentioned substantially less often than any other date.  It's been that way since long before 9/11 and I have no idea why.

His results suggest that our months do have some kind of internal structure that is not illustrated on our usual calendars.  Those simply display numbers in a grid of weeks.  Yet Mr Munroe’s findings suggest that there is more to it than that.  As the mouseover text points out, in eleven of twelve months the eleventh is mentioned much less often than any other date.  The exception is of course September, where references to the events of 11 September 2001 propel that date to the very top of the list of frequently named dates.  Yet this pattern was already well-established before 2001, and there is no obvious explanation for it.

Some variations in frequency are relatively easy to explain.  The first of the month is usually a day when many bills and reports are due, and so the first is among the most named dates of each month.  Holidays are also prominent; notice, though, that the eleventh of November, Veterans’ Day in the USA and Remembrance Day in the countries of the Commonwealth, is no bigger on Mr Munroe’s chart than the little elevenths of the other months.  The 15th of April is quite prominent; that has traditionally been the day when income taxes were due in the USA.  But, in addition to the mystery of the obscured elevenths, we also notice that the fourth and nineteenth are bigger than average in most months.  Why would that be?  Perhaps it doesn’t mean anything, but perhaps there is some explanation that would become obvious if we were in the habit of thinking of calendars, not as the grids of weeks that are usually tacked on walls in the West, but as structures built around major days, structures like those the ancient Romans used.  Too bad we can’t raise some ancient Romans from the dead and put them in charge of investigating the question, their perspective might result in a most fruitful study.  I suppose the best substitute would be classical scholars who have spent time studying the ancient Roman calendar.