From: Edward C. Zimmermann
> Imagine I want to document a date I know took place at the start of Dec.
> 1990 but I'm not sure if it was the 1st, 2nd or 3rd of the month.. and
> want to check.. The expression "1990-12-0u" seems fine and dandy...
> when I've checked that it was the 3rd I'd fill it in.. That's why I
> write "1990-12-0u" and not "1990-12"
Yes, we understand, month vs. year precision. But you achieve month
precision with "1990-12-uu". And really, the actual theoretical precision
you would want to achieve (for your example) is to narrow it to months 1-3,
which "1990-12-0u" doesn't do anyway. "1990-12-0u" would match the precision
you want only if your use case was "I know it was one of the first ten
months." If you really had a practical use case where you know it was
during the first ten months, then the argument for "1990-12-0u" would be
> I would argue that u as blanks to be filled in.. should be allowed
> anyone might see fit to use them. I personally might not ever see the
> for an expression such as "uuu2-12-22" but who am I to say "no no"..?
I thought there is general consensus that we don't want to be creating
unecessary complexity by adding features that nobody has asked for but that
someone might need someday.
> > 3. Year and month specified, day unspecified (And similarly no
> for just one digit of the day unspecified, as in 1990-12-0u.)
> Beware the use of the predicate "unspecified". In the date "1990"
> the month or day are specified but its something quite different from
> uu-uu". If one can specify the month of a date that is expressed in
> then the date has at least month precision.. similarly if one specify
> month and day it has day precision.. "can specify" and "specify" are
> not, I
> must stress, the same. With "1990-12-uu" I explicitly state that I "can
> specify" the day but has not yet--- I plan on filling in the blanks..
> With "1990-12" I say that I can't--- obviously with more information....
Ok, I will try to tighten up the prose is this area.