Why the Watchtower Study Edition, January 2018, page 26, says:
"Satan’s world has made humans suffer for some 6,000 years."? How do they get that calculation?
HOW TO BE HAPPY
19. Who can never be really happy?
19 Satan’s world has made humans suffer for some 6,000 years. Now, in the last days of this system, the earth is full of people who focus on themselves, money, and pleasures. They think of what they can get and make their own desires the main thing in life. But people like that cannot be truly happy! In contrast, the Bible says: “Happy is the one who has the God of Jacob as his helper, whose hope is in Jehovah his God.”—Psalm 146:5.
https://wol.jw.org/en/wol/d/r1/lp-e/402018246