Our hoster automatically installs a WordPress version which is a service I appreciate. Anyways they installed the German version for us and now it seems that some contents (e.g. time of a post, some link-titles etc.) appear in German. I already changed all meta-headers to en-US but this does not change anything.
On my local machine in comparison to that I installed the English version and everything is in English. So I guess it must be because of the German WordPress version.