In a large saucepan, cook the wild rice according to package directions. Use 1 cup stock in place of 1 cup of the water. Use , meanwhile, cook brown rice in the remaining 2 cups stock. Combine and add sage and thyme.
In a large skillet, saute celery and onion in oil until tender. Stir in cranberries, pecans and parsley. Remove from the heat. Stir in rice mixture.
Cut squash in half widthwise. Remove and discard seeds and membranes. With a sharp knife, cut a thin slice from the bottom of each half so squash sits flat. Fill squash halves with about 1/2 cup rice mixture. Place in a greased 15-in. x 10-in. x 1-in. baking pan. Pour water into pan.
Coat one side of a large piece of heavy-duty foil with nonstick cooking spray. Cover pan tightly with foil, coated side down. Bake at 350 degrees F for 50-60 minutes or until squash is tender.