Happy New Year?

Dec 24, 2010

Things We Take for Granted

Calendar in the Sky?

Calendar Systems

I’ve just read through some of the Wikipedia articles related to calendars, calendar years, calendar systems, pre-Julian Roman calendar, Julian calendar, Gregorian calendar, and months.  Yeah, I know.  Why would I do a thing like that to myself?  : )  Anyway, it was a fascinating little journey with lots of little “oh, really?” and “so that’s where that came from” moments.  There were also lots of little “aha!”s and “oh, right”s and “ah …”s and “oh, ok, that makes sense”es and “hey, that’s cool!“s.  What a story is behind yet another thing we take for granted — the way we account for days, months, and years both currently and for historical purposes.

One of the reasons I found the story so appealing is it works into the “directly-experience-able” “natural facts” (in this case, observed phases of the moon and observed transition points in when days change from getting shorter to getting longer) vs. “made-up and agreed-to concepts used to deal with natural facts” (in this case, “year”, “month”, “equinox”, “ides”, “nones”, and even “calendar” from “kalendar” from “kalling” or “calling” debt payments due on the first of the month in the ancient Roman Republic) dichotomy that always fascinates me.

From those examples, it’s also clear that another reason it appealed to me is it fits my lifelong interest in understanding how words, expressions, ideas, beliefs, customs, rules, laws, procedures, and other aspects of the world around us came to be what they are.

I titled this page, “Happy New Year?”, because one part of the story is the “starting date” of the “year” has changed a lot over the “centuries”.  I’ll explain.  …  What?  Thanks?  Thanks for what? Nevermind?  Well, ok …

Anyway, when I started this page by typing, “Dec 24, 2010”, I had a whole new appreciation for what it means and where it came from.  I’ll explain that too.  …  What?  Well, ok, but thanks for what?  Thanks for what warning?  …

: )

What’s In a Word?

Take a look at the words, September, October, November, and December.  Even if you know English, you probably, like me, never really noticed that “Oct-ober” and “Dec-ember” were like “oct-opus” and “dec-imal system” which have meanings related to “eight” and “ten.”  Even if you noticed, you probably just passed over it since those are the 10th and 12th, not the 8th and 10th, “months” of the “year.”

On the other hand, suppose you know some French (like me), some Spanish (me a little bit), some Latin (me not much), or some of all three.  The pattern becomes more compelling.  The “Sept” and “Oct” and “Nov” and “Dec” are a clear “7 8 9 10” pattern.  But they are the “9 10 11 12” months.


I’ll come back to this in a moment.

A Calendar is a Call-endar

Meanwhile, here’s another interesting point.  Think about this.  In the ancient Roman Republic, there were no cell phones to pick up to find out what is the date of today.  There also was no internet yet, so you couldn’t flip open the laptop and get the date there.  No cable tv, tv, or radio to get the date from there.

So how do you know when to make your monthly payments on your financial debts?

Answer:  When the first crescent moon appears in the sky after a sunset.  I’m serious.  That’s what they did.  Everybody agreed to use something they all could see in the sky as their way of knowing what day the debt payments were due.  When you first see this:

Crescent Moon - Time to Pay the Bills in the Ancient Roman Republic

… you know the payment is due and your creditor knows you’re supposed to show up with the dough.  The day in each month that has the first appearance of the crescent moon, the day the payment is “called for” — in Latin, “kalled for” (or something close to that) — is the day in the day in the month called, in Latin, the “kallendae” (or something close to that).

Counting Down vs. Counting Up

The paper calendars — or I don’t know, maybe stone, clay, or wood calendars — they made in those days showed the days, not as “27th day in March”, but as “15 days before kallendae, bill payment day, in the month of April.”  The next day was called, “14 days before kallendae in the  month of April.”  The next day was called, “13 days before April’s kallendae.”  The next day was called, “12 before April kallendae.”  And so forth.  While we count days up in a month from 1 to 28, 29, 30, or 31, the people of the ancient Roman Republic counted days down to the bill payment due date, the day of the month’s first crescent moon.

At first, I’m guessing people used the crescent moon as their reminder to go pay the bill in an after-the-fact way.  “ok, there’s the crescent moon.  time to take the cash to ol’ louie the bill collector.”  I’m guessing that, later, people wanted to predict with accuracy when the crescent moon would first appear.  If you think about it, given that months seem to have different lengths for some reason, that’s a pretty big challenge.  It’s easy for use to just use “30 days have september …” and other memory aids, or to just look at a calendar to know how many days we have left before the 1st of the month, but — in ancient Rome — somebody had to get really good at knowing which days the crescent moon would first appear in each month.  Could you or I predict when that physical event will next occur without looking it up in an almanac or on the internet?  Interesting problem.

Julian Calendar = Julius

Julius who?  Answer:  Julius was a man who was bothered by the fact that …

Gregorian Calendar = Gregory

The main calendar system in the modern world.

Gregory who?  Answer:  Gregory was a man who was bothered by the fact that the date for the annual celebration of the Easter holiday — based on the “solar equinox” — kept slipping further away away its original date in March toward dates earlier in March and was headed slowly and inexorably toward becoming dates in the latter part of February.

1 “Year” = 12 “Monthly” Cycles of the Moon?

It makes sense that ancient man (and woman) would first try to measure long periods of time using the sun’s ups and downs, the moon’s comings and goings, and the comings and goings of the seasons.  What else did they have?  No calendars, cellphones with the date, computers with the date, radio or tv telling the date, or internet.  It also makes sense that, at first , it would seem like there were about 12 comings and goings of the moon between when it started, for example, getting cold last time and when it started getting cold this time.  Give the lunar comings and goings twelve different names and have a sense from the current moon cycle’s name what season it was.  That would have seemed maybe ok from just one year to the next, but after a decade or two, that would become a problem.  Here’s why:  As the following Wikipedia statement shows, the position of the named months would shift about 10 days, about 1/3 of a month, every year.   If a month called, “January,” were in the center of the cold season one year, it would, in 18 years, be in the center of the hot season.  (18 years * 1/3 month per year = 18/3 = 6 months.)

Wikipedia:  “The lunar year comprises twelve full cycles of the phases of the Moon, as seen from Earth. It has a duration of approximately 354.37 days.”

We now know the “year” that keeps the seasons coming and going on the same dates is 365 and 1/4 24-hour “days” plus, importantly, about 11 minutes.  It was the difference of about 10 days between lunar and solar years that gave rise to most of the world adopting the solar calendar which eventually became the Julian version of the solar calendar.  It was the 11 minutes difference that was part of the change to the Gregorian version of the solar calendar.

Hebrew Calendar


Islamic Calendar


What Got This Calendar Stuff Started?

A discussion with a certain scholar — actually, I should say, a gentleman and a scholar — about calculus led to verifying that Newton was the inventor of calculus.

Which led to the new info (for me) that, these days, both Newton and Leibniz are credited with independently inventing and developing the calculus used today.  That led to checking dates the two math wizards lived.

I had known Leibniz was a math scholar, but mostly remembered him as the philosopher Voltaire was said to be poking fun at in his philosophical novel, Candide. Dr. Pangloss was Candide’s travelling companion through his many adventures and misadventures.  Throughout the novel, Dr. Pangloss expounds on Philosophico-Theologico-Cosmogonology, his theory centered on the idea that the reality we experience is “the best of all possible worlds.”  I never investigated Leibniz’ works to find out if Voltaire was fairly or unfairly having Dr. Pangloss speak for him.

Checking Isaac Newton’s dates led me to something I’d never noticed before in Wikipedia — two sets of birth and death dates for the same person with links for “OS”, an explanation of “Old Style” vs. “New Style” dates.   Both the birth and death dates differed by a year and 11 days.  My interest in Newton’s dates, of course, was not to be that precise.  It was enough for me to know Newton lived from the mid-1600s through the early 1700s.  But I found the two sets of dates confusing at first, had to slow down a bit, and noticed the links to “OS”.  This shifted the curiosity energy from simply finishing the calculus discussion by refreshing memory of Newton’s dates to opening up a new subject of calendar systems in general.

Notice in the Wikipedia excerpt below, that the change from Old Style to New Style dates changes Newton’s birth and death dates by a year and 11 days.  It changes both the year of his birth and the year of his death.  That made me a little curious.

“Sir Isaac Newton (4 January 1643 – 31 March 1727 [OS: 25 December 1642 – 20 March 1726])[1] was an English physicistmathematicianastronomernatural philosopheralchemist, and theologian, and is considered by many scholars and members of the general public to be one of the most influential people in human history. His Philosophiæ Naturalis Principia Mathematica (Latin for “Mathematical Principles of Natural Philosophy”; usually called the Principia), published in 1687, is probably the most important scientific book ever written. It lays the groundwork for most of classical mechanics. In this work, Newton described universal gravitationand the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, by demonstrating the consistency between Kepler’s laws of planetary motion and his theory of gravitation; thus removing the last doubts about heliocentrismand advancing the Scientific Revolution.

Newton built the first practical reflecting telescope[7] and developed a theory of colour based on the observation that a prismdecomposes white light into the many colours that form the visible spectrum. He also formulated an empirical law of cooling and studied the speed of sound.

In mathematics, Newton shares the credit with Gottfried Leibniz for the development of differential and integral calculus. He also demonstrated the generalised binomial theorem, developed Newton’s method for approximatingthe roots of a function, and contributed to the study of power series.”

There’s another interesting thing in the Wikipedia article on Newton.  Notice in the next paragraph, the last paragraph of the article’s introduction, that Newton, one of the most famous physical plane scientists, wrote even more about spiritual plane matters that we never hear about.

Newton was also highly religious. He was an unorthodox Christian, and during his lifetime actually wrote more on Biblical hermeneutics and occult studies than on science and mathematics, the subjects he is mainly associated with.”

Clicking on the OS (“Old Style” dates) link led to this page which led to discovering the messy quagmire that historians sometimes have to work with when establishing dates within the same country in different time periods and between different countries in the same and different time periods.  The  more modern part of the messiness (1500s and 1600s) comes from dealing with Jan 1 through March 25 in the various European countries who, after the fall of Rome with its Julian calendar, each adopting slightly different official/fiscal years during the Middle Ages.  Later, in response to Pope Gregory’s initiative, the countries adopted the Gregorian calendar at different times over about a hundred years.  The total picture of establishing dates involves the various changes in pre-Julian Roman, Julian Roman, post-Rome pre-Gregorian European, post-Gregorian European transitional, and, finally — whew! — our current Gregorian calendar.

As it turns out, the stable calendar we take for granted today (stable from the view of physical seasons and from the view of administration and history) has only been around since the 1500s and 1600s.  Have to check that.  I’m pretty sure that, once all the countries made the changes to the Gregorian calendar, which corrected the 11-minute difference between the 365 1/4 day “year” and the actual length of a “year,” the situation became much more orderly and simple.

Anyway, all of that reminded me that I’d never really understood what the famous Julian vs. Gregorian calendar issues were about.  And what I also wondered was why “January 1” was chosen for the start date of a “new year”.  I know “equinoxes” are something physical — are “natural facts”, (vs. man-made conceptual inventions).  As are things like, “first appearances of the crescent moon” and the date of “the full moon.”  But I’m still wondering if Jan 1 has any intrinsic significance that makes it unavoidable, compelling, or at least attractive.  I’ve learned A LOT of other things about the nature and history of calendar systems, but still haven’t seen any intrinsic physical basis for picking Jan 1.  It looks like the Roman leader who added January and February to the 10-month “calendar of Romulus” just somehow had the new January picked up where the old calendar (that amazingly a lot of winter days … the “calendar of Romulus”, apparently, didn’t deal with some days at all.  i’m sure that made sense somehow at the time, but seems silly viewed from 2010) left off.

So a lot of old and new questions have been answered.  And the question of why Jan 1 is still open.

But that’s how this inquiry into calendar systems got started.   Like a lot of interesting things.  Pretty much by accident of noticing one thing while thinking about something else.


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