If...

..I owned a grocery store, and I was closing early because of the power being out across half the city, I would put a sign stating so on the ENTRANCE, not in little letters on the EXIT.
And if I had one of the those little signs you can program to say different things, I would have it say what time i was closing, instead of letting the customers drive in, park, get to the doors, and then find the doors locked.
I'm just sayin'.