Use rfc-3339 instead:
One of the problems with iso8601 was parsing the (optional) T letter (hah!):
sam$ date --iso-8601=seconds 2006-03-22T22:01:57+0900
Evidently `date` sometimes got confused with the T and treated it as a military timezone hence b0rking up the backwards conversion. So iso8601 is depreciated… well at least you don’t have to pay to read the entire rfc-3339 spec.
As some of you may or not know, I have an uber cool Letter generator that uses latex to produce a pleasant professional PDF letter from a Web form. Does it work with CJK characters? No. Will it? Perhaps. Sadly tetex3 seems to be missing OpenType support. Though another Mac specific latex package called xetex> does.