Patrick,
From this page: https://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html
Here is what Z returns
Looks like that is consistent with what you are getting. Not sure exactly what you’re looking for, but maybe you can find a format that suits your needs on the page referenced above.
***EDIT***
just looked a bit further down on the page and it seems like ZZZ might return what you want if XXX doesn’t work: