Welcome Mat
I was walking up to the door of a boutique home furnishings store at the same time that a couple was arriving. As the gentleman reached his arm around my left to open the door for me and his companion, he read aloud the sign on the door: "No Strollers. No food or drink in the store. No public restrooms. No soliciting." He followed with "No sales!" so quickly one would have thought that it, too, was on the sign. The store owner followed all of the right rules of crafting a sign, but still sent an inadvertent and potentially costly message to a potential customer. It didn't matter that the paper was of high quality, that the text was in a nice font or that the sign was framed in a beautiful wood frame. The sign made that person feel unwelcomed before he ever crossed the threshold. No matter how nice the product or staff or layout of the store inside, he had hit the mute button.

Anyone Home?
Take your business hours sign. It is designed to tell customers a very important message - when you are open for business. While I don't disagree that it is a necessary but somewhat boring sign, there are other ways to express your store's personality than by making it sound like you aren't willing to provide the information that they are interested in. In each of these examples, the business hours have been cleverly (read: a creative way to turn potential customers away) posted in lengthy detail. One is professionally crafted and adhered, yes adhered to the store window. The other was created with care for color and graphic detail yet without concern for misspellings.

Come On In
A better option is to simply provide the information that the customer is looking for. Your font and color choices extend your store's signature style to the sign. The addition of your logo helps the customer remember the name of your store. One could argue that the word "closed" is a negative and best not used at all. Consider "by appointment" if you actually offer them or even "by www.storename.com (Facebook, Twitter) 24-hours a day" instead.

What Time Is It?
Years ago, I came across a profile on a store called Ta Da!. Their business hours sign was beautifully framed in an ornate gold frame hung from a ribbon in their front window. As I typically do, I looked so deeply into the photograph that I was able to adapt their idea for my store's business hours sign; down to the "Hours of Enjoyment." I love the idea of telling my customers that we don't have business hours, we have Hours of Enjoyment! Ours is crafted of two frames hinged together so that customers see a framed sign from both the interior (some will note the hours as they are departing for future reference) and the exterior so that we can update the signs as they fade in the hot Texas sun.
This idea could be adapted to a number of store types. For a toy store "Hours of All Out Fun", for a design based store "Hours of Inspiration", for a spa "Hours of Pampering". You get the idea.

Positive Messages
And to really lay out the proverbial welcome mat, what about this idea? We have a framed dry erase board that we place on an easel outside of our store. Each day we use it to introduce new products, announce an upcoming event, or get a chuckle with a witty quote. While it is difficult to know when one of our loyal customers is coming by, when we do, we use the easel to welcome them. That's what this orthodontist does to welcome first time patients to his office. Just think of the message that you'll send to the bride-to-be as she comes to register in your store! Just think of the message that you'll send to everyone else that happens by.
Successful retail means using every opportunity to tell a customer that they are important. Today's consumer is more attentive than ever. The bottom line is that they notice messaging missteps and fortunately, the messaging marvels. Use it to your advantage when you create your next window display...and business hours sign.