```You want 195x to mean "the 1950s"?  (Rather than the meaning I had thought
we decided on.)

Since you are the only one (as far as I know) who cares about the x
notation, it's fine with me.

--Ray

> -----Original Message-----
> From: Discussion of the Developing Date/Time Standards
> [mailto:[log in to unmask]] On Behalf Of Edward C. Zimmermann
> Sent: Tuesday, June 28, 2011 9:31 AM
> Subject: Re: [DATETIME] On the usefulness of x
>
> On Mon, 27 Jun 2011 16:57:19 -0400, Ray Denenberg wrote
> > > {1950..1959} means the set (all of) dates 1959 through 1959. It is
> > > an array of dates expressed with a precision of year.
> > > The expression 195x, by contrast, is neither an array nor an
> > > expression with a precision of year but a date with a precision of
> 10 years.
> >
> > Are you perhaps confusing 'x' with 'u'?
>
> No. The expression 195u has a precision of year. It is used to express
> a date in year precision where the year, however, is not (yet) known.
> The expression, by contast, 195x is of decade precision (10 years) and
> does not express any uncertainty. The expression, for example, "The
> journal was published in 195u" I would take to imply that it was
> published in some year in the 1950s but its uncertain, at this time,
> which. The expression, by contrast, "The journal was published 195x" I
> would take to mean that the said journal was published in at least one
> of the years in the 1950s.
> 195u -----------> 1 year in the range 1950 to 1959. The date is
> expressed with precision of year.
> 195x -----------> 1 or MORE years in the range 1950 to 1959 expressed
> with the precision of decade.
>
> >
> > 199u means "one of the years 1990, 1991, 1992, etc."
> > 199x is supposed to mean "ALL of the years 1990, 1991, 1992, etc."
>
> That is the difference in our views and why I think "x" is needed and
> can't be  replaced by {..} expressions. {1950..1959) can mean ALL of
> the years since its an expression of an array of dates with an implicit
> measurement precision of year.
> If one agrees that the expression "195x" has a precision of decade than
> it can't be ALL since that would entail a readability (precision) of
> year.
> The contruct 'x' (from right to left) I took to represent the
> expressions "1950s", 18th Century etc.
> The expression 195x (1950s) is, I think, like reading a short
> thermometer with ticks every 10 degrees. Its hard to talk about where,
> for example, 33 degrees is..  its not readable to degree.
> Its, again, like 1999. That expression does not mean "all" days, hours,
> minutes or .. If I say that a journal was published in 1999 I mean that
> at least one issue (perhaps more) was published in 1999 but not that an
> issue was published every second. "1999" means one or more and not ALL.
> The expression "1999" has a precision of year so I can't read precisely
> month, day, hour, minute, second ...
>
> >
> > The example cited is someone listing years of publication. For
> example
> > for
> a
> > book published in 1992, 1996, and 1998 you could list its years of
> > publication as {1992, 1996, 1998}.
> >
> > But say it was published in 1988, 1990, 1991, 1992, 1993, 1994, 1995,
> > 1996, 1997, 1998, 1999, 2002, and 2004.
> >
> > You could list its years of publication as {1988, 199x, 2002, 2004}.
> >
> > This is what we decided many months ago.
>
> I did not decide this :-)
> I was always, I think, speaking of precision. Wildcards never really
> interested me except in queries. That is why I see 195x as being
> something to implement (well its been implemented already by me as I
> have interpreted
> it) but not 1x59. I can see some interesting questions expressable with
> wildcards such as "turn of the century", "mid century" etc. but see
> them on the side of query and less on the side of date representation
> for storage--- I would implement these, just as generalized 'u', in the
> query engine (state
> machine) and not in my indexer (data storage model).
>
> >
> > --Ray
>
>
> --
>
> Edward C. Zimmermann, NONMONOTONIC LAB
> http://www.nonmonotonic.net
> Umsatz-St-ID: DE130492967
```