Change Language / Time Format

Hi,

my WP is running in german language (de), but Shiftee does not display german text and date format, how can i set my calendars to the right format, i tried to translate the .po, but it seems to be misformated, please help!

My page is not online yet, because of those troubles, i cant show it to my client like this,

thanks and best regards from vienna, austria, mo