Back in the 1970's, when I had my "Little Used Book Shop" in Northampton, one of the nice features of it -- one of the nice features of self-employment, generally -- was that I made my own hours. Occasionally, during the day I had to run out to do errands or take a couple of hours for lunch or some such. To let customers know that I would be returning at some point, I made a variety of signs to hang on my store door. This is one of those signs.
I constructed it with a wheel in the back that I could turn to indicate in a little cut-out window when I would be open for business again. -- PL