@diamondiiz suggests that the decade of the 30s (and maybe he also meant to include the decade of the 20s, but I don't really know)
No, my understanding of a decade is not an overlapping decade as you may imagine. In the 1920s there were many references to 1874 as Jesus' return not just a few - many. As TD stated, the idea to change Jesus' return from 1874 to 1914 started to form in the early 1930s but officially WTS changed it in 1943. The only thing that Russell taught about 1914 that wasn't changed was that it was the end of Gentile Times and that's it. Even when calculating the gentile times, Russell used 606BC based on his understanding that 536BC was Cyrus' first year not that the Jews returned to their homeland after a year of traveling as appears to be todays JW teaching. JW today teach the Russell was their first president and they don't exclude him as a nut that he was so you have to accept that WTS has been a false prophet from the start preaching and teaching 1874 as Jesus' invisible return for over 50 years before they changed their dogma. De 18:20-22 clearly applies to WTS!!! If you get confused about Russell's calculation grab Thy Kingdom Come book and read it. While 1914 may not have been viewed as Armageddon taught by JWs today it had a similar meaning for Russell and his followers. After all, if the governments were to be destroyed by Jesus in 1914 or 1915 or shortly after(again in the early 1910s Russell had cold feet so needed to adjust his teaching).....the teaching of the end of the system of things was expected then and not in the distance future and that's what they've been Preaching and Teaching. False prophets is what they came to be and that's only the start of the fraud that wts is.
“‘However, the prophet who presumes to speak in my name a word that I have not commanded him to speak or who speaks in the name of other gods, that prophet must die. 21 And in case you should say in your heart: “How shall we know the word that Jehovah has not spoken?” 22 when the prophet speaks in the name of Jehovah and the word does not occur or come true, that is the word that Jehovah did not speak. With presumptuousness the prophet spoke it. You must not get frightened at him.’
The point not to be missed here though is that Jehovah's Witnesses today teach that Jesus' presence began in 1914, and what is more, his presence has not yet ended, but it continues to this very day.
Who cares what JWs teach today!!! In 30 years from now they may teach that Jesus returned in 2014 because they misapplied the 100 years somewhere and so what? Everyone will have to just ignore the fact the 1914 has been taught for a long period of time? There is no point that is being missed by TD but by you. The point is that JWs hide the facts from those that they recruit. In fact is that most witnesses today don't even have a true understanding of their own past.