Resent-From: cbmvax!uunet!PICA.ARMY.MIL!protin
Resent-Message-Id: <9108071635.AA07600@relay1.UU.NET>
          14 Sep 90 23:37 EDT
From: cbmvax!uunet!math.ucla.edu!jimc
Message-Id: <9009131829.AA01782@julia.math.ucla.edu>
To: lojban-list@snark.thyrsus.com
Cc: "Arthur W. Protin Jr." (GC-ACCURATE) <protin@PICA.ARMY.MIL>
Subject: Re: times, dates, images, and S-W 
In-Reply-To: Your message of "Mon, 06 Aug 90 16:59:59 EDT."
             <9008061659.aa08340@COR4.PICA.ARMY.MIL> 
Date: Thu, 13 Sep 90 11:29:43 -0700
Resent-Date:  Wed, 7 Aug 91 12:28:24 EDT
Resent-To: John Cowan <cowan@snark.thyrsus.com>
Status: RO

I also am a little slow getting caught up.  On Arthur Protin's use of
yymmdd date format, there is in fact an ISO standard prescribing this
order.  I don't have the number right handy but it's in the library and
I could re-check features if anyone's interested.  Here's my
recollection from several years ago: 

The date consists of fields of digits separated by anything else.  The
standard wasn't exactly clear what was or was not allowed as
separators. The first number is a year.  I don't remember if there was
a prescription for what to do with two-digit years.  Next is a month
and last is a day. Time-of-day was not addressed.  The Gregorian
calendar is (tacitly?) assumed.  

In -gua!spi I have a "vector" construct in which X2, X3, ... (as many
as needed) are expressions and X1 is an ordered list with these
members. This fits right in with dates; X1 (one of these vectors) is
the date of event X2 starting with unit X3 (default years) with
calendar style X4.  A transitive compound with "hours" gives you
time-of-day.  

I wonder if time-of-day or date should have the preference?  In a
language with a very mechanistic style you must choose one; you can't
rely on semantics to suggest which is meant, but you don't want
separate primitive words for both concepts.  

> Now if you want to redefine all our clocks to fill a day with 100,000
> units approximately equal to 0.864 seconds ...

In the late 50's, Donald Knuth (yes, THE Donald Knuth) published a piece
entitled "The Potrzebie System of Units" in Mad Magazine, in which he
did just that.  If I remember right, 1E-5 * day was called a "martin".
The article helped me greatly to understand unit systems and their
metrological considerations -- much more than the explanations I was
getting in school.  

		-- jimc