suggestion for new date data types: 1.1 xml schema

Hi,
    XML schema 1.1 should have date types that can be grouped together
into custom date formats.
 
    The current date types with dashes('-) are problematic.
 
    To ensure backward compatibility there should be new date
types(maybe called ddates) with a delimiter facet(default of nothing).
    
    example: ddate with delimeter of '/' or ''(nothing) or '-' or '
'(space) etc.
 
    The current work around using strings an dregular expressions is not
acceptable as leap year and sanity checks(for Dec 35) in dates are not
possible.
    
    If there are any work arounds for dates please let me know.
 
    Also when will 1.1 be official.  What is the expected timelines for
it to be done?
 
    thanks
            Dhruv