Translation (WP, *not* Posts)

Dear all

I am currently installing WP as a back-end for a german website. I have some tiny little problems with translating stuff that seems to be built into WordPress directly (I translated the theme stuff without problems).

First thing is the name of the months – like “January”, “February” etc. I want these to be “Januar”, “Februar”, etc. This might be a PHP problem, but still maybe someone can help?

Also, I haven’t found some mouseover stuff in my theme, specifically I am using the “Categories” widget to display all categories, pretty standard, but the title to the categories-links apparently is something like “display all posts filed under xyz” – again, this needs translation, how can I do this?

This is at the moment all I can spot – everything else seems to be translated through the theme.

Thanks
thomas