Let me state, at the offset, I am not opposed to garage or yard sales. I enjoy going to them and buying things that I don’t need. I have, on occasion, had such sales myself.
I implore you, though, the day that the sales are over, to please take a few minutes to remove your signs. I recall one in my neighborhood that was up for over a month.
The above should also apply to lost pets. If they haven’t been recovered in a month, it would be safe to assume they are gone.