6045 2008-09-09 02:08:35 +0000 Single timeline value space for dateTime -- compatible or no? 2008-09-24 20:19:16 +0000 1 1 1 Unclassified XML Schema Datatypes: XSD Part 2 1.1 only Macintosh Mac System 9.x RESOLVED FIXED http://lists.w3.org/Archives/Public/www-xml-schema-comments/2008JulSep/0135.html resolved P2 normal --- 1 cmsmcq cmsmcq pfps www-xml-schema-comments oldest_to_newest 21834 0 cmsmcq 2008-09-09 02:08:35 +0000 In email to the XML Schema comments list on 5 September 2008 (http://lists.w3.org/Archives/Public/www-xml-schema-comments/2008JulSep/0135.html), Peter F. Patel-Schneider raised the following issue (among others): 1/ Time instants ... 1.3/ Value space for time instants The WG will be using a value space for time instants that consists of a single timeline. The WG believes that this is compatible with the treatment of time instants in the LC draft. 21840 1 cmsmcq 2008-09-09 02:49:59 +0000 Speaking for myself, I think the intention you describe is indeed compatible with XSD 1.1's definition of the datatypes in question. It should be pointed out, however, that the timeline in question is not necessarily continous -- or at least, that its mapping onto UTC is not continuous. Since XSD 1.1 does not provide for, support, use, or countenance leap seconds, the values of our dateTime datatype map discontinuously onto the UTC timeline. If this matters in your use of the type, be careful. (Of course, many systems handle leap seconds in roughly the same way XSD does; by scrupulously noting their existence, but ignoring them for almost all practical purposes.) 21878 2 cmsmcq 2008-09-12 16:02:48 +0000 The XML Schema WG discussed this issue in its call of today, and agreed (a) with your belief that what you describe appears to be compatible with XSD 1.1, and (b) with the note in comment #1 that you should be careful about leap seconds. Accordingly, I'm marking this as RESOLVED. 22032 3 pfps 2008-09-24 20:19:16 +0000 Agreed, and thanks. As far as OWL is concerned, there is no way to notice the discontinuity, but applications may indeed need to be careful.