There is a post on this site, from many years ago, buried way back in the thousands or 10's or thousands of posts, that describes the GB at the time having a near apoplectic fit over that "in our twentieth century" phrase. Somehow it got past the proofreaders and into the millions of printed copies.
And then of course, inevitably, thousands of calls and letters poured into Bethel asking if this was a promise, if there really was a hard deadline of 11 years until Armageddon's start. Of course, they had to backpedal when replying to those calls and letters. Which was of course embarrassing, hence the near-apoplectic fit.
There's just so much stuff on this site, that thread would be virtually impossible to find now.