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Well, it looks like it's broken, then—at least the ruby parser (
https://github.com/inukshuk/edtf-ruby) and the javascript parser (
https://github.com/inukshuk/edtf.js) agree—neither considers 1990?-uu-uu a
valid EDTF date, which agrees with my reading of the BNF.

- David Newbury
-----------------------------------
p. (773) 547-2272
e. [log in to unmask]

On Thu, Mar 9, 2017 at 11:50 AM, E. Zimmermann <[log in to unmask]> wrote:

> The ? applies to the 1990. If the BNF grammar disallows this then it is
> broken!
>
>
>
>
>
> *From:* Discussion of the Developing Date/Time Standards [mailto:
> [log in to unmask]] *On Behalf Of *David Newbury
> *Sent:* Thursday, March 09, 2017 4:34 PM
>
> *To:* [log in to unmask]
> *Subject:* Re: Uncertain, unspecified dates
>
>
>
> 1990?-uu-uu appears to be what state my intentions, but from my reading of
> the BNF it does not appear to be a valid EDTF date.
>
>
>
> (internalUncertainOrApproximate and internalUnspecified appear to be
> mutually exclusive)
>
>
>
>
>
>
> - David Newbury
> -----------------------------------
> p. (773) 547-2272
> e. [log in to unmask]
>
>
>
> On Thu, Mar 9, 2017 at 9:58 AM, E. Zimmermann <[log in to unmask]> wrote:
>
> If I am uncertain of the year being 1990 and don’t yet know the month and
> day but expect to be able to fill them in at some time…..
>
> 1990?-uu-uu
>
>
>
> Uncertainty is quite different from “approximately”..   That means “in the
> neighborhood of”…
>
>
>
> So if I think it was somewhere around 1990 etc. etc.
>
> 1990~-uu-uu
>
>
>
> The character ‘u’ is more than just a placeholder BUT I think it is
> probably best to think of them as just that..
>
>
>
> The problem with (uu)? is that it is saying “I expect to be able to put in
> some unreliable numbers”.. Normally we expect or hope to get good data..
> Once we collect something we can speak about trust.. like.. well I got a
> day but I don’t 100% trust it.. In fact at some point we did have a notion
> of belief in the reliability of a value..
>
> See EDTF’s list of possible future features..
>
>
>
> Right now ‘?’ means just “unreliable”..  (its level being unstated  whence
> implementation defined and might include another man’s date without
> qualification.. See the current discussion on “alternative facts”)
>
>
>
>
>
> *From:* Discussion of the Developing Date/Time Standards [mailto:
> [log in to unmask]] *On Behalf Of *David Newbury
> *Sent:* Thursday, March 09, 2017 3:34 PM
> *To:* [log in to unmask]
> *Subject:* Re: Uncertain, unspecified dates
>
>
>
> What I am trying to express is:
>
>
>
> I know an event happened on a specific day.  My research has indicated
> that it took place on some specific day in 1990, but has not indicated yet
> a month or day, but I do not believe the knowledge is unattainable.
>
>
>
> That is appropriately recorded as 1990-uu-uu
>
>
>
> However, I am uncertain that my research is correct.  It may, in fact,
> have been 1995, or 1850, or some other year entirely.  I would like to
> indicate that the date, while known, is untrustworthy.  In my reading of
> the specification, that appears to be the meaning of a date such as
> 1990-10-10?:  That it is a recorded date, but that is is uncertain or
> untrustworthy.
>
>
>
> I would like to be able to state both of these things, and they seem to
> not be in conflict.  My certainty/uncertainty of a date is not related to
> the precision to which I know that date.
>
>
>
>
> - David Newbury
> -----------------------------------
> p. (773) 547-2272
> e. [log in to unmask]
>
>
>
> On Thu, Mar 9, 2017 at 7:34 AM, E. Zimmermann <[log in to unmask]> wrote:
>
> What does 1990-uu-uu say? It says that I KNOW that an event took place in
> 1990. I currently don’t know the day or month but I expect to get this data
> at some time in the future.
>
>
>
> What could uncertainty mean here? That I don’t expect to get the missing
> data or that I’m not quite sure that I don’t know the data?
>
> The ‘u’ character in your use case is nothing other than a placeholder..
> Perhaps you get some information that it was on the 15th of some month
> BUT you are uncertain.. that is where the ‘?’ as an expression of
> uncertainty enters..
>
>
>
> To round up:
>
> -       You know that an event took place an some instant in a day
>
> -       You know that it occurred in 1990
>
> -       You don’t know the month or day (yet)
>
> -       You may NEVER be able to know the month or day—but you may one
> day and by best practice you indeed expect to be able to “fill in the
> blanks”..
>
> 1990-uu-uu
>
>
>
> If, however, you can’t measure the day or even month (and with current
> knowledge don’t really expect to).. But know it was 1990 then
>
>
>
> 1990
>
>
>
> Just as a sample I put on a scale may weigh 20g on my crude balance.. It
> weighs 20g.. If later I get a better balance.. I can change the
> information. Say to 19.789g
>
> Same with dates..  Dates are not carved in stone!
>
>
>
> The new addition we have provided to ISO 8601 is that we know have finally
> a concept in date analogous to weighs and lengths.
>
>
>
>
>
> *From:* Discussion of the Developing Date/Time Standards [mailto:
> [log in to unmask]] *On Behalf Of *David Newbury
> *Sent:* Wednesday, March 08, 2017 8:55 PM
> *To:* [log in to unmask]
> *Subject:* Uncertain, unspecified dates
>
>
>
> I'm trying to implement a system using EDTF, and I'm trying to record an
> event which:
>
>
>
> 1. Took place with day precision. (It is a discrete event, and my system
> does not record with more than day precision)
>
> 2. Is uncertain (I have a date, but I am unsure if it is accurate)
>
> 3. Is unspecified.  (I know the year it took place in, but I cannot yet
> determine the month or day).
>
>
>
> It seems logical that this would be recorded as  *1990-uu-uu?*, but that
> does not appear to be a valid EDTF date.
>
>
>
> Is there a reason that "uncertain" and "unspecified" cannot be used
> together?  They seem to be orthogonal concerns.
>
>
>
> - David Newbury
> -----------------------------------
> p. (773) 547-2272
> e. [log in to unmask]
>
>
>
>
>