So in review by using the WTS's its own literature we can see that the organization's leaders had used the 6000 year dating calculation at least 4 different times starting right back to 1874 to always create an end calculated time of 6000 years.
This shows clearly how indulgently corrupt this organization was and is when it came to developing its own doctrines.
God would naturally choose the biggest bullshitters to teach his Gospel, or maybe its just bunch of men trying to promote the distribution of the literature it publishes.