0 days without x

Signs which highlight that 0 days had gone by without X happening, X often being a variable for "accidents", "incidents", "nonsense", and so on. Originally used in workplace settings to make workers conscious of health and safety responsibilities, to avoid something from happening that might, for example, cause the death of another coworker.

A screencap from the Simpsons would become adopted as a meme representation of such signs, substituting the X for more humorous situations.