Whatever reasoning the WTS had in the past is out the window now that they have quietly dropped the idea that a creative day is 7,000 years long to the more ambiguous thousands of years or millenia. Below last mention I can find of a 7,000 year creative day.
*** w87 1/1 p. 30 Questions From Readers ***
Second, a study of the fulfillment of Bible prophecy and of our location in the stream of time strongly indicate that each of the creative days (Genesis, chapter 1) is 7,000 years long. It is understood that Christ’s reign of a thousand years will bring to a close God’s 7,000-year ‘rest day,’ the last ‘day’ of the creative week. (Revelation 20:6; Genesis 2:2, 3) Based on this reasoning, the entire creative week would be 49,000 years long.
Ambiguous thousands of years
*** g04 1/22 p. 23 Why I Believe the Bible—A Nuclear Scientist Tells His Story ***
Rather, it reveals that the creative "days" encompass thousands of years.
*** w03 2/1 p. 4 How to Cultivate a Balanced View of Work ***
For example, when reviewing what he had done at the end of the six creative "days," or long periods of time,
*** w96 4/1 p. 13 par. 10 Praise the King of Eternity! ***
Wonderful developments took place on earth during the six creative "days" of Genesis chapter 1, each day covering thousands of years.
*** w93 1/1 p. 4 Our Grand Creator and His Works ***
In an orderly sequence of six ‘creative days,’ each thousands of years in length,
As the other question: not a simple answer, eh? God rested at the end of the 6th day....7th day a rest day? Per the WTS Paul wrote in his time that humans were still in God's rest day. (Hebrews 4:1-16)
(Hebrews 4:1-16) 4
Therefore, since a promise is left of entering into his rest, let us fear that sometime someone of YOU may seem to have fallen short of it. 2
For we have had the good news declared to us also, even as they also had; but the word which was heard did not benefit them, because they were not united by faith with those who did hear. 3
For we who have exercised faith do enter into the rest, just as he has said: "So I swore in my anger, ‘They shall not enter into my rest,’" although his works were finished from the founding of the world. 4
For in one place he has said of the seventh day as follows: "And God rested on the seventh day from all his works," 5
and again in this place: "They shall not enter into my rest." 6
Since, therefore, it remains for some to enter into it, and those to whom the good news was first declared did not enter in because of disobedience, 7
he again marks off a certain day by saying after so long a time in David’s [psalm] "Today"; just as it has been said above: "Today if YOU people listen to his own voice, do not harden YOUR hearts." 8
For if Joshua had led them into a place of rest, [God] would not afterward have spoken of another day. 9
So there remains a sabbath resting for the people of God. 10
For the man that has entered into [God’s] rest has also himself rested from his own works, just as God did from his own. 11
Let us therefore do our utmost to enter into that rest, for fear anyone should fall in the same pattern of disobedience. 12
For the word of God is alive and exerts power and is sharper than any two-edged sword and pierces even to the dividing of soul and spirit, and of joints and [their] marrow, and [is] able to discern thoughts and intentions of [the] heart. 13
And there is not a creation that is not manifest to his sight, but all things are naked and openly exposed to the eyes of him with whom we have an accounting. 14
Seeing, therefore, that we have a great high priest who has passed through the heavens, Jesus the Son of God, let us hold onto [our] confessing of [him]. 15
For we have as high priest, not one who cannot sympathize with our weaknesses, but one who has been tested in all respects like ourselves, but without sin. 16
Let us, therefore, approach with freeness of speech to the throne of undeserved kindness, that we may obtain mercy and find undeserved kindness for help at the right time.
So there are 2 parts to this question: is the 7th creative day a rest day and second is it 7,000 years long (any more in the WTS doctrine)