This is an NSFormatter subclass to parse ISO 8601 strings into NSDate  
objects and format NSDate objects into ISO 8601 strings. It supports  
calendar, week, and ordinal date formats in both directions.
New in version 0.5 is the NSFormatter nature. Previously, the parser  
and unparser were categories upon NSCalendarDate. The new version is  
completely NSCalendarDate-free, which means (a) it requires Tiger and  
(b) it won't break when NSCalendarDate goes away.
Also new is the Bitbucket repository, where you can file bug reports.