Usage and Grammar
Q. If I am referring to the year 1900, do I say “at the turn of the nineteenth century” or “at the turn of the twentieth century”? Most of the writers I’ve edited use the latter, but I’ve always thought the former makes more sense, in that the nineteenth century is doing the actual “turning.” I’ve asked other editors and no one seems to know, so I’ve always edited around this.
A. Unfortunately, as you have discovered, both phrases are ambiguous. Instead, write “at the beginning of the twentieth century,” or “at the end of the nineteenth century,” or “in the years around 1900.” “The turn of the century” is useful only when the context makes it obvious which turn you’re talking about. See CMOS 9.32.