A DESCRIPTION OF THE REQUEST :
The standard XML formats for datetime, etc. cannot be
implemented by a SimpleDateFormat. This is because SimpleDateFormat
does not support generating timezones in the "+HH:MM" format, as
required by the XML standard. It us thus impossible to create a
standard XML value representing a datetime, such
as "2006-12-23T14:03:02Z-08:00" without having to generate the text
in custom-written Java code.

See http://www.w3.org/TR/xmlschema-2/#dateTime for the XML format.

Also see bug #4919632. This problem has existed for a long time.
XML is not a new format! Please fix this issue!

JUSTIFICATION :
The implementation is trivial, and the lack of this feature needlessly complicates Java/XML interoperability.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
I would like to see a new format specifier, say "Q", that generates a timezone in the format "+HH:MM" or "-HH:MM", and can also parse these formats. Then I could specify a standard XML dateTime as "yyyy-MM-dd'T'HH:mm:ss'Z'Q".
ACTUAL -
Timezones can be generated in formats "GMT+HH:MM", and in format "HHMM", but not "

---------- BEGIN SOURCE ----------
N/A, because the feature does not exist.
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
      final SimpleDateFormat df = new SimpleDateFormat( "yyyy-MM-dd'T'HH:mm:ss'Z'" );
      output.write( df.format( when ) );

      int nOffset = TimeUtils.millisToMinutes( df.getTimeZone().getOffset( when.getTime() ) );
      if( nOffset < 0 )
      {
         output.write( "-" );
         nOffset = -nOffset;
      }
      else
         output.write( "+" );

      // write hours and minutes of timezone offset
      final DecimalFormat nf = (DecimalFormat)NumberFormat.getInstance();
      nf.applyPattern( "00" );
      output.write( nf.format( nOffset / 60 ) );
      output.write( ":" );
      output.write( nf.format( nOffset % 60 ) );