Astute reader John Wall points to a sentence in today’s New York Times: “The Guardian said on Monday that it intended to cut its costs sharply in an effort to reduce its losses and break even at an operating level in three years’ time.”
He notes, “I think of the phrase with ‘time’ preceded by the possessive form of a measure of time as a very British expression, as in ‘two hours’ time’ or, in this case ‘three years’ time.’ … A native USA speaker/writer of English would, I think, write ‘in three years,’ without the possessive apostrophe or the word ‘time.'”
I was not aware of the Britishness of the formulation, but John is correct, according to this Google Ngrams Viewer graph showing the relative frequency of the phrase “years time” in British and U.S. sources. (Ngram viewer doesn’t recognize apostrophes, so I left it out; and I didn’t include the number of years, so as to include a wider range of citations.)
Like a number of other NOOBs, “___ years’ time” wasn’t especially British until fairly recently–in this case, the 1920s. It steadily increased in popularity till the late 1980s–the moment when the modest American revival commenced.