Approval in backend

backend/de/basis.json

@@ -209,6 +209,9 @@
         "starting_before": "Beginnt vor",
         "due_before": "F\u00e4llig vor",
         "completed_after": "Beendet nach",
-        "completed_before": "Beendet vor"
+        "completed_before": "Beendet vor",
+        "current": "Derzeitig",
+        "upcoming": "Kommend",
+        "past": "Vergangen"
     }
 }