I read Brevard Childs' "A Study of the Formula 'Unto This Day'", which appeared in the September 1, 1963 Journal of Biblical Literature. Why did I read this article? Throughout the Hebrew Bible, we see the phrase "unto this day," and there are biblical scholars who have tried to date parts of the Bible according to that expression. For example, I Kings 12:19 says that Israel rebelled against the house of David unto this day, which implies to many scholars that this particular layer of the text was written when Northern Israel still existed---which would be prior to the destruction of Northern Israel in 722 B.C.E., and of Judah in 587 B.C.E.
But I wondered how those who believed that much of the Bible was composed in Israel's exilic or post-exilic periods would interact with the "unto this day" texts. Would they see "unto this day" as a device to make the texts appear older than they really were? After all, in the days of antiquity, older was better. I noticed Childs' article in a footnote of a book I was reading, and I thought that perhaps he would discuss other scholarly options than "this text is pre-exilic on account of the 'unto this day' statements."
But Childs didn't really address this issue. The issue that was more on his mind was whether or not the "unto this day" statement demonstrated that the text was an etiology---a story that addresses how something that the readers knew about came to be. Childs' conclusion is that, in many cases, a story was not invented to explain how something came to be "unto this day." Rather, there was a story, and a later redactor attached "unto this day" to it because it related to his and his audience's historical context. So the story was not originally an etiology, but it was made into one by a later redactor (or, actually, Childs calls it a "personal testimony" and distinguishes it from an etiology). Childs notices the same sort of thing in Greek works, such as the history by Herodotus: Herodotus tells a story that he's heard, then he relates it to conditions in his own time. Childs takes "unto this day" as an indicator of when the redactor lived---for he understands "this day" to be the time of the redactor.