JWS today do not know that the WTS used the 6000 years of mankind's existence 3 times in the 20th century , starting around the early 1900's.
So what time were the brothers running ahead of themselves ?
Maybe they were propagating a date to drawn attention to the literature they were publishing
As in ..... " Christ has returned the end of this system of things is upon us "
The WTS has been involved in commercialized false prophet charlatanism for over 140 years.
To confirm that all you have to do is read its literature starting back to the late 1800's