Won't even hurt the stations. If we assume a certain portion of the "gas-free for a day" people stock up the day before, and the rest load up the day after, I don't think the gas stations are going to be terribly worried. If anything, they'll look upon it as a blessing -- a day off. As I said in another thread, you want to do something about fuel prices? Sell the car and cycle to work. If not, quit whining.