A careful study of the Creation account in Genesis reveals no conflict with established scientific facts. For that reason, Jehovah’s Witnesses disagree with “Christian” Fundamentalists and many Young Earth Creationists. (Also see: The Bible’s Viewpoint - Does Science Contradict the Genesis Account? g 9/06 pp. 18-20; Watchtower Online Library)
The following is an excerpt from the g 9/06 p. 3 "Whom Should You Believe?":
ARE JEHOVAH’S WITNESSES CREATIONISTS?
Jehovah’s Witnesses believe the creation account as recorded in the Bible book of Genesis. However, Jehovah’s Witnesses are not what you might think of as creationists. Why not? First, many creationists believe that the universe and the earth and all life on it were created in six 24-hour days some 10,000 years ago. This, however, is not what the Bible teaches. Also, creationists have embraced many doctrines that lack support in the Bible. Jehovah’s Witnesses base their religious teachings solely on God’s Word.
Furthermore, in some lands the term “creationist” is synonymous with Fundamentalist groups that actively engage in politics. These groups attempt to pressure politicians, judges, and educators into adopting laws and teachings that conform to the creationists’ religious code.
Jehovah’s Witnesses are politically neutral. They respect the right of governments to make and enforce laws. (Romans 13:1-7) However, they take seriously Jesus’ statement that they are “no part of the world.” (John 17:14-16) In their public ministry, they offer people the chance to learn the benefits of living by God’s standards. But they do not violate their Christian neutrality by supporting the efforts of Fundamentalist groups that try to establish civil laws that would force others to adopt Bible standards.—John 18:36.
For more, see:
Do Jehovah's Witnesses Believe in Creationism? (JW.ORG)
Did God create the earth in just six 24-hour days, as some creationists claim? (AWAKE! JANUARY 2014; JW.ORG)
Does Science Contradict the Genesis Account? (Defend Jehovah's Witnesses)
The Creative 'Days' - How Long Was Each 'Day' and Were All 'Days' Uniform in Length? (Defend Jehovah's Witnesses)
How Does the Bible Show That the Creative Days Were Longer Than 24 Hours Each? (Defend Jehovah's Witnesses)
Genesis - Links to Information (Defend Jehovah's Witnesses)
Day - Links to Information (Defend Jehovah's Witnesses)