request iso-8601 date types

Request that XML Schema provide support for all ISO-8601 date types.  
ISO-8601 has already done the hard work in defining these lexical 
forms, and companies are using them for data interchange.  Why are only 
a subset supported by XML Schema?  Notably missing: Ordinal Date, Week 
Date and Time Interval.

Either add the missing types as built-in types or in a W3C-blessed type 
library or allow users to properly define them, using some sort of 
compound simple types.

xan