I would use 3 switch functions and basically bring it all together and get each part separately first.
Here is the formula (I don’t know German and just looked up the translations change as you need of course 
)
{{switch(formatDate(now; “dddd”); “Monday”; “Montag”; “Tuesday”; “Dienstag”; “Wednesday”; “Mittwoch”; “Thursday”; “Donnerstag”; “Friday”; “Freitag”; “Saturday”; “Samstag”; “Sunday”; “Sonntag”)}}, {{switch(formatDate(now; “MMMM”); “January”; “Januar”; “February”; “Februar”; “March”; “März”; “April”; “April”; “May”; “Mai”; “June”; “Juni”; “July”; “Juli”; “August”; “August”; “September”; “September”; “October”; “Oktober”; “November”; “November”; “December”; “Dezember”)}} {{formatDate(now; “Do”)}}