[Mulgara-dev] XSD Date/Time Corruption reproducible
Andrae Muys
andrae at netymon.com
Sat Jan 27 06:50:56 UTC 2007
On 27/01/2007, at 4:29 PM, Paul Gearon wrote:
> On Jan 26, 2007, at 7:07 PM, Andrae Muys wrote:
>> Actually in discussion last night it occurred to me that this
>> isn't going to work either. This problem arose because localtime
>> is not continuous. The above proposal doesn't work because
>> localtime isn't monotonic either. Specifically there is no
>> localtime lexical form for the last hour of DST - java assumes
>> standard-time for ambiguous timestamps.
>>
>> I think we always have to use timezones, ie. option 1. isn't
>> really an option.
>
> I disagree. From a string representational point of view (which is
> what toString() is all about) then the ambiguous time is just
> fine. That's EXACTLY what people see. Internally the times are
> just fine, and the system knows that 1:30am the first time through
> is actually earlier than 1:15am the second time through. It just
> get printed in a funny way for people. But it's *supposed* to.
>
> If it's important that it get printed in an unambiguous way, then
> we provide the option for it.
Well I'm not convinced, so I will wait to see what other people say
about this.
>> Moreover we also do need to think about adding a localtime
>> datatype - one that actually stores a date/time rather than a
>> timestamp. This is important for issues such as calendar
>> applications and event management where the location/timezone is
>> stored independently of the date/time and the value cannot be
>> represented as a time_t. For now users who need to do this can
>> reify their dates, but it would be nice to support them natively.
>
> I'm reluctant to add any datatype that is not in XSD. For a start,
> what is the datatype URL? It won't be standard RDF.
I'm not aware of anything in RDF that mandates that a datatype URI
has to be a XML Schema Datatype. Yes XSD is important to support,
but there are numerous other datatype standards out there, and it is
perfectly legitimate to use them. I am not the slightest bit
hesitant to provide non-XSD datatypes - especially where the
datatypes in question are not defined in XSD.
Andrae
--
Andrae Muys
andrae at netymon.com
Principal Mulgara Consultant
Netymon Pty Ltd
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