ok, im assuming the CDR you are using is taking you through a danger area. It will be plannable (i.e CDR1) outside the hours of activity of that area. however , we as ATC may also make use of that same route if the danger area closes early or is closed for a period of time notified to us (CDR3) , i.e tactically.
So in your case you may only only flight plan this route during the times it is notified as being available, otherwise flightplan around. There is nothing to stop you asking in the air if the danger area affecting the CDR has, or is closed early and whether the route is available. the worst we can do is say no!