Access application controller from didinsertelement view

I want to access application controller so I can get/set a variable (selected_date) value.

myApp.ApplicationController = Ember.Controller.extend({
    selected_date: null,
  actions: {
    }
  }
});

I would like to make edits to selected_date from a view (didinsertelement), the controller for the view is:

myApp.CreportController = Ember.ObjectController.extend({
    needs: "application"
});