- From: Alan Ruttenberg <alanruttenberg@gmail.com>
- Date: Fri, 25 Jul 2008 11:53:02 -0400
- To: Uli Sattler <sattler@cs.man.ac.uk>
- Cc: "Deborah L. McGuinness" <dlm@ksl.stanford.edu>, Michael Smith <msmith@clarkparsia.com>, public-owl-wg <public-owl-wg@w3.org>
On Jul 25, 2008, at 8:55 AM, Uli Sattler wrote: > > On 25 Jul 2008, at 13:33, Deborah L. McGuinness wrote: > >> >> ps. if i do not have a time zone, i can look for the location of >> the instrument / observatory that generated it and then figure out >> time zone based on lat / long and date of instrument. >> we currently do not have moving instruments yet. >> > > good - so if you were to do this, you could (with no overhead to > speak of), > > - instead of adding the timezone information > - convert the time in the 'owl-standard-time-zone-time' > > Hence not having time zones shouldn't be a huge problem?! Hi Uli, I think this will almost certainly be wrong if owl-standard-time-zone- time is any specific time zone. The statement Breakfast is at 7AM (unfortunately) doesn't mean 7 AM owl-standard-time-zone-time. It means local time, wherever local is. If we are making a commitment to a specific timezone for times without timezones, the supporting timezones in constants is trivial - an addition or subtraction. In that case we could, instead of committing to a single owl-standard- time-zone-time, make owl-standard-time-zone-time be the local time zone, with the determination of local being up to the implementation. -Alan > > > Cheers, Uli > >> Alan Ruttenberg wrote: >>> Hi Deb, >>> >>> Could you say a bit about how the datetime data is used? Are you >>> simply doing retrieval? Sorting (if so, how to compare those with/ >>> without timezone?) >>> >>> Best, >>> Alan >>> >>> On Jul 25, 2008, at 7:45 AM, Deborah L. McGuinness wrote: >>> >>>> >>>> My applications make heavy use of xsd datetime. >>>> my issue in applications is that i have unpredictable data details. >>>> sometimes i have year, month, day, (sometimes with and sometimes >>>> without timezone) >>>> and sometimes i also have hour and minutes (and sometimes even >>>> seconds) sometimes with and sometimes without timezone. >>>> >>>> so i would NOT support a requirement that all data either does or >>>> does have a time zone ; >>>> i would support an approach that allows me to have optional >>>> timezones. >>>> >>>> thanks, >>>> deborah >>>> Michael Smith wrote: >>>>> On Thu, 2008-07-24 at 12:27 +0100, Uli Sattler wrote: >>>>> >>>>> >>>>>> the 'easy' support for time that I was advocating yesterday >>>>>> seems to fit in nicely with this: >>>>>> >>>>>> - absence of a time zone (so I guess we would only support a >>>>>> *restriction* of xsd:dateTime, but this should be ok) >>>>>> >>>>> >>>>> I think we either need all constants to have a timezone, or >>>>> none. I >>>>> prefer the first based on the assumption that more data "in the >>>>> wild" >>>>> has timezones, and that such data is more completely defined. >>>>> >>>>> >>>>>> - the value space is continuous (since seconds are decimals >>>>>> between 0 and 60, according to my reading of Mike's [1]) and >>>>>> therefor, from an algorithms perspective, isomorphic to >>>>>> owl:number and thus it shouldn't be too much of a burden on >>>>>> the implementors. >>>>>> >>>>> >>>>> Agreed. >>>>> >>>>> >>>> >>>> >>> >> >> >
Received on Friday, 25 July 2008 15:53:49 UTC