While on an 11g BPEL implementation, I had a fairly simple request to convert a date format from Julian to calendar.  I shrugged off the request as simple, and thought it shouldn't take more than a few minutes.  I was entertained by the fact that you can convert a date to Julian, but nothing was provided, unless I missed it, to convert a date from Julian!

Not that Julian is used very often, but when it is, most of the time it needs to be converted to calendar date for better recognition.