[LEAPSECS] Calendars count days - clocks divide them up

[Rob Seaman]

Warner Losh wrote:

>> It is gratifying to see how flawlessly this standard is implemented,

>> despite over 40 years of it being the standard. I guess the far older

>> expectation that every minute has 60 seconds is kinda deeply engrained...

> 

> Wikipedia drily notes that "Between 1000 (when al-Biruni used seconds) and

> 1960 the second was defined as 1/86,400 of a mean solar day".  That 1960

> endpoint to which it refers is the transition to the ephemeris second.

> Rubber-seconds UTC, which has occasional minutes with !=60 seconds,

> comes along in 1961.  So we've got around 960 years of the second only

> being a subdivision of the minute, versus 53 years or so of seconds

> being more complicated than that.

> 

> -zefram


Standards aren't just randomly chosen, they express an underlying model of how the universe works.  Implicit in the standards expressing, say, units of electric current and resistance are observations and inferences with names like "Ohm's Law".  The proposed new formalism for the SI (metric) system relies on this explicitly:

	https://commons.wikimedia.org/wiki/File:Relations_between_new_SI_units_definitions.png
	http://nvlpubs.nist.gov/nistpubs/jres/116/6/V116.N06.A01.pdf

The conceptual model underlying the SI-second is frequency.  Civil timekeeping simply represents another standard.  Conceptual models fail if an attempt is made to force fit them together.

Speaking of frequency, consider the words that people use:

	http://www.wordfrequency.info/free.asp?s=y

(This is American English - statistics for other languages would be welcome.)  The ranks and frequencies of usage of words related to timekeeping:

	 54		year	(n)		769254
	 90		day	(n)		432773
	188		week	(n)		199268
	237		month	(n)		162685
	273		hour	(n)		138955
	309		minute	(n)		126660
	683		second	(n)		 56022

The word "day" is used more than seven times as frequently as the word "second" (as a noun).  The three calendar words (year/month/day) are more prevalent than the three clock words (hour/minute/second) by greater than four to one.  Even "century" is used more frequently than "second", and "decade" is used almost as frequently: 

	606		century	(n)		  65667
	731		decade	(n)		  53727

Whatever underlying model of human cognition, these data cannot be used to argue that our parsing of time into units of days is irrelevant to society.  "Day" is more frequently used than key nouns like man, woman and child.  The noun "second" is less frequently used than other words descriptive of days like morning and night - and the combined usage of the terms AM and PM is 50% more frequent than "second".

In fact while all the words above are nouns the rankings are listed for all parts of speech.  If you scroll down the very long list you will find that the top five most frequently used nouns themselves are:

	time
	year
	people
	way
	day

People perceive time
in a way that descends from
a year and a day

Rob