Here is a beginning to understanding the length of generations. Not all dates are exact and it is uncertain as to when the beginning and end of each generation is exactly but with additional study it becomes clear that a Biblical generation is considered to be 70 years.
Start with Matthew1:17.
Matthew 1:17 Therefore all the generations from Abraham down to David are 14 generations; and from David down to the Babylonian captivity are 14 generations; and from the Babylonian captivity down to the anointed, are 14 generations.
There are 14 generations from Abraham down to David.
From the source: http://media.aish.com/documents/Spiro_History_Timeline.PDF
Abraham was born in 1812 BC. Follow the Generations to David whos reign began in 877 BC. Thats 941 years. Divide that by 14 and you get 67.21 years. Given some slight variables that still gives very close to the 70 year generation.
There are other sources and examples but I thought this one would allow for the seed for study.
This same time line says the Babylonian Captivity was "422 BCE".
14 x your figure for a "generation" 67.21 == 940.94, as you said.
941-422 = 519.
So EITHER "the Anointed" appeared in the first quarter of the 6th century of the Common Era
OR one of the figures is wrong.
Try this: 422/14 = 30.14 which is less than half of three score and ten, but that puts us at 1 AD.
There's a problem.
What is it with guys, carrying on with the incessant arguments over such a simple thing???