Anyway. It's arguably of benefit to the workers, as it guarantees them at least some time off during the week.
I've never quite understood this. I work a 42 hour week. If I work more I get paid more. If my boss asks me to work an 84 hour week and I agree then its a) my choice and b) overtime.
As long as you can't get sacked for not doing overtime, and as long as you get paid for doing said overtime, why can't the stores decide? If they can't get the staff to work it they'll either not open early or will have to pay more.
In the end it'll probably result in not much changing because to open longer would cost more for a little more income. But shouldn't that be upto the market to decide?