How many miles should I put on my shoes before half marathon?

I am running a half marathon and want to know how many miles I should have on my shoes for the race. I don't want to wear brand new ones, but also don't want them to be worn down. Where would you say that happy medium is?|||about a week is good, to make sure they do not have irritating spots and such.|||Wear them in so they are comfortable and softer to allow you to run to your full capacity :) good luck with your marathon