Last day of a month or a year in XSLT

i'm having some issues to make this work on a transformation in Oracle Bpel I receive a date, and a group criteria: mm/yyyy or: yyyy So, I have to construct an ' start day' and an 'end date' if the criteria is mm/yyyy, the start day will be the first day of the given month/year, and the end date, the last day of the given month/year.

I know there is a function called: functx:last-day-of-month

But I cannot make this work in Oracle Bpel, so that's why i'm using this answer: Last day of previous month in XSLT Just want to know how to do that with any given month.

Thanks a lot for any help.