Depends on what conditions you store them in. If you can put them in a vacuum sealed bag or a zip-loc freezer bag and pop them in the freezer. They will last longer that way, but at a couple of weeks you should be fine.
yeah, i've had crushed grain in my fridge or freezer for like 2 or 3 months before using and the recipe came out right on the numbers. even at room temp, i would bet a month or so wouldn't be out of the question.