birthday nil fix

app/models/fetprofile.rb

@@ -54,10 +54,14 @@ end
     self.plz.to_s + ' ' + self.city.to_s + connector.to_s + self.street.to_s
   end
   def birthday
+    unless self.birth_month.nil? || self.birth_day.nil?
     if self.birth_year.nil? || self.birth_year.zero?
       Date.new( Date.today.year,self.birth_month,self.birth_day)
     else
       Date.new( self.birth_year,self.birth_month,self.birth_day)
     end
+    else
+      nil
+    end
   end
 end

app/views/fetprofiles/_interninfo.html.erb

@@ -1,5 +1,5 @@
 <p>
-<b>Geburtstag</b> <%= I18n.l(interninfo.birthday,format: :short) %>
+<b>Geburtstag</b> <%= I18n.l(interninfo.birthday,format: :short) unless interninfo.birthday.nil?%>
 </p>
 <p>
   <b>Adresse:</b>