Add translations for various purposes in nodac

nodac/en/languser.json

@@ -17,6 +17,8 @@
         "admin": "Admin",
         "groupadmin": "Group admin",
         "editor": "Editor",
-        "switch_language": "Switch language"
+        "switch_language": "Switch language",
+        "month": "month",
+        "year": "year"
     }
 }