Re: Comments on http://www.w3.org/TR/timezone/ of 13 October 2005

On 4 Aug 2008, at 18:05 , Phillips, Addison wrote:

> ...
> I should note that we did solicit and receive comments from the  
> schema WG, particularly from Ashok, when this Note was originally  
> written. We (the authors) understood the reasons for Schema's  
> design decisions and any negative connotations were, I stress, not  
> intentional--excepting to point out that zoneoffsets cannot do  
> certain things.

OK.  Point well taken.  I apologize for my hypersensitivity; mostly,
the public discussion of XSD has given me good opportunities to
develop a thick skin, but every now and then something gets  
through ... :)


>> (2) The passage quoted also seems, in the phrase "choose which zone
>> offset to use", to overlook the possibility of representing such
>> wall-clock times with structures like an offset-free xsd:time value
>> in one attribute or element and a code for the time zone (e.g. PT
>> or America/Los_Angeles or ...) in another.
>
> That is, of course, a possibility. The point we should be making  
> here is that you need a *structure* if you need actual time zone  
> operations. I should point out that most applications don't need  
> time zones at all. One of the revision points would be to enumerate  
> the use cases. It's more useful to say "if (situation x) do (y)"  
> than merely say "xs:date doesn't work for this".

Yes, I think that's true.

>
>>
>> (3) in section 1.4.1, the phrase
>>
>>      a meeting that is always UTC-08:00 (and thus at 7:00 in the
>>      morning in Pacific time during parts of the year)
>>
>> seems unclear to this reader.  What does it mean for a meeting to
>> "be UTC-08:00"?  I think you mean "a meeting that is always
>> scheduled for 08:00-08:00", but only you can say for certain.
>>
>
> This is actually a scenario you should be familiar with from W3C:  
> twice a year most of us move our teleconferences to account for  
> daylight savings coming on/going off in various parts of the world.  
> Since these aren't synchronized in time, we sometimes have a couple  
> of weeks where the conference happens at the same universal time  
> ("08:00-08:00"), but at a different wall time (Pacific time moves  
> from 8 to 7, for instance). That's because Zakim doesn't change to  
> Summer Time the same date as say London.

I am indeed familiar with that scenario; it's just that the sentence  
seems
to be phrased a little loosely.  A strict reading, or a reader who is  
having
trouble following the document, might object that a meeting can always
be scheduled at a particular clock time in a particular time zone (or
at a particular time zone offset), but it's as unusual to say that a  
meeting
is "always UTC-08:00" as it would be to invite you to attend a meeting
scheduled for Pacific Daylight Time, without mentioning a particular
time of day, in that time zone (or time zone offset).


best regards,

Michael Sperberg-McQueen

Received on Tuesday, 5 August 2008 21:15:56 UTC