I came across some interesting quotes on why the literal Creation of 7 days is foundational to our beliefs. Just 5 years after Darwin's ''Origin of the Species'' Ellen White wrote:

"...I was then carried back to the creation and was shown that the first week, in which God performed the work of creation in six days and rested on the seventh day, was just like every other week. The great God in his days of creation and day of rest, measured off the first cycle as a sample for successive weeks till the close of time..."

"...The supposition, that the events of the first week required seven vast, indefinite periods for their accomplishment, strikes directly at the foundation of the Sabbath of the fourth commandment. It makes indefinite and obscure that which God has made very plain..."

"..Geologists claim that the world is very much older than the Bible record makes it. They reject the Bible record, because of those things which are to them evidences from the earth itself, that the world has existed tens of thousands of years. And many who profess to believe the Bible record are at a loss to account for wonderful things which are found in the earth, with the view that creation week was only seven literal days, and that the world is now only about six thousand years old. These, to free themselves of difficulties thrown in their way, ... adopt the view that the six days of creation were six vast, indefinite periods, and the day of God's rest was another indefinite period; making senseless the fourth commandment of God's holy law Just how God accomplished the work of creation he has never revealed to mortals. His creative works are just as incomprehensible as his existence." 3SG 90 Chapter IX. - Disguised Infidelity
(ALSO see that in THE SPIRIT OF PROPHECY VOL. 1 (1870) CHAPTER 8. DISGUISED INFIDELITY Ellen White, pages 85-93)

Here is the White Estate on Ellen Whites view..
"Although Ellen White uses the phrase “unity in diversity,”[16] and stated “Instructors in our schools should never be bound about by being told that they are to teach only what has been taught hitherto,”[17] she maintained that the landmarks and pillars of Adventist truth were to remain. Concepts that impact the science of geology which she “was shown” to be identified as permanent include six literal, empirical, historical 24-hour days of creation, culminating with a literal 24-hour Sabbath day of rest, and human life on earth non-existent before the literal creation week described in Genesis"
(Interpreting Ellen G. White’s Earth History Comments
Faith and Science Conference II, Glacier View, Colorado
August 13-21, 2003, Presented By Cindy Tutsch, Associate Director Ellen G. White Estate)
[16] Francis D. Nichol, SDA Bible Commentary, 7 vols. plus supplement. (Washington, D.C.: Review and Herald Publishing Association, 1970), 6:1083.
[17] Ellen G. White, “Manuscript 8a,” 1888, Ellen G. White Estate, Silver Spring, MD.

Here is a piece on this in a Review article on how the intrepretation of Creation affects beliefs......

"...“In the beginning God created the heavens and the earth” (Gen. 1:1).*

This first verse of Scripture outlines in the most concise terms “when,” “how,” “by whom,” and “in what manner” the world was created. What follows is a concise description of creation in six “evenings and mornings.” Some scholars have suggested that each day could represent long periods of time; or that there are chronological gaps in the narrative of Genesis 1. Recent studies show, however, that in terms of the syntax, articular usage, singular gender, time boundaries, and other factors, the word “day” (Hebrew yôm) means a literal 24-hour period of time. Furthermore, these days were intended by the writer to be sequential and chronological.1 ....


Many Christians today take a middle stance between creation and pure evolution to harmonize science and the Bible. In doing so some support the theory of progressive creation, a belief that life began on earth some 600 million years ago or more with God’s intervention at crucial stages in the vertical radiation of species. Others have advanced to theistic evolution, maintaining that God initiated the whole process millions of years ago and left it to develop on its own. But what are the implications of these views for the biblical gospel? I call your attention to 12 considerations.

1. Inspiration of the Bible. The belief in progressive creation or theistic evolution challenges the trustworthiness of Scripture. The creation of all life in six literal days does not jive with these models, so other explanations must be offered. This casts doubt on the Bible as the inspired Word of God (2 Peter 1:20, 21; 2 Tim. 3:16, 17; John 17:17; Ps. 119:105). Jesus Himself spoke in Luke 11:50, 51 of Abel, the son of Adam, in an illustration that took for granted the historicity of this early chapter in Genesis. These words of Christ would require reinterpretation, thus further undermining the confidence of Christ’s teachings.5

2. The Character of God. Within an evolutionary perspective the God who notices when a sparrow falls (Matt. 10:29) would have initiated and intended that animals and humans should suffer for millennia in their competitive struggle for survival. Furthermore, God would be misleading humanity by stating that the world was created in six days and that He spoke these things into existence when He did not (Ex. 20:11; Mark 13:19). This would impugn the character of the Godhead.6 Christ was called the “last Adam” (1 Cor. 15:45, 47). What would this mean if sin was not introduced through the first Adam?

3. The Nature of Humans. There is no room for low self-esteem when we realize that “man” (Hebrew ’adam), both male and female, was made in God’s image (Gen. 1:27; 5:1, 2). God formed us with His hands (Gen. 2:7, 21, 22). Humankind was the apex of creation and was given the privilege of direct communication with God. We have the motivation to live lives reflective of His character because our bodies are the “temple of the Holy Spirit” (1 Cor. 6:19), created in God’s image. Progressive creation views human beings as but another species in the evolutionary process, removing the element of divine relationship and responsibility entirely from humanity.

4. Death Before Sin. Paul writes in Romans 5-8 on sin and the beauty of salvation. “Sin entered the world through one man, and death through sin, and in this way death came to all men” (Rom. 5:12). Genesis 3 tells of the fall of humanity after creation, which begins the great controversy on this earth. But an evolutionary perspective would have death present for 600 million years prior to Adam. This has serious implications for the biblical teaching of the origin of sin, Christ’s substitutionary death on the cross, and the plan of salvation. If death is not related to sin, then the wages of sin is not death, and Christ would have had no reason to die on the cross of Calvary for our sins.7

5. Worship. Worship today as experienced in the church is intricately tied to creation. God’s creation was made to worship and glorify its Creator. Such worship is to take place on the seventh-day Sabbath (Ex. 20:9, 10). The theme of worship is emphasized again in the call to those on earth just before Christ’s second coming to worship the One “who made the heavens, the earth, the sea and the springs of water” (Rev. 14:7). If God did not create in six literal days, then we must question the motives of our worshiping experience on the seventh.

6. God’s Remnant People. Through-out history God maintained a remnant (2 Chron. 30:6; Ezra 9:14, 15; Isa. 10:20-22; Jer. 42:2; Eze. 6:8; 14:22). This recurring theme is particularly attached to the end-time church that proclaims the three angels’ messages. The remnant “follow the Lamb wherever he goes” (Rev. 14:4) and “keep the commandments of God and the faith of Jesus” (verse 12, NKJV). This includes creation. If progressive creation and theistic evolution are gaining hold today in mainstream Christianity, we must ask, What is divine truth as taught in Scripture? These are the truths upheld by the remnant.

7. The Law and the Sabbath. Progressive creation and theistic evolution directly challenge the institution of the seventh-day Sabbath. Indeed, the seven-day week has no point of origin outside of creation. It is not fixed to lunar movements or rotations of the earth. The seventh-day Sabbath is thus intimately tied to the creation. The fourth commandment (Ex. 20:9, 10) reiterates this and adds further weight to the importance of the Sabbath (cf. Ps. 104).

8. Stewardship. In the beginning God established a plan for the care of His creation. Adam named the animals, and humans were commanded to “rule over the fish of the sea and the birds of the air and over every living creature that moves on the ground” (Gen. 1:28). Here God provided the means of ecological stewardship, designating us to care for everything He made. Progressive creationism and theistic evolution imply that humans are in mutual competition with all species, which they must dominate in order to survive. This view is contrary to Scripture (see Ps. 8:4-8).

9. Marriage. At creation marriage is introduced as a divine institution. Adam was to “be joined to his wife” and they were to “become one flesh” (Gen. 2:24, NKJV). It was a unique gift that God gave to humanity, and it was in the creation of both male and female that we were made in His image. Anthropological explanations of marriage must find cultural reasons for this institution that in evolutionary terms are seen again as a matter of survival and primarily biological. In Scripture marriage is ordained by God, falling uniquely into the creation account.

10. Christ’s Ministry in Heaven. One of the many aspects of the sanctuary doctrine is the final vindication of God’s character. Part of Christ’s heavenly ministry today is to demonstrate that God is not responsible for sin, but that it came through the seduction of Satan. But the confusion of sin with death, and the mystery that would surround the origin of evil if Genesis 3 is regarded as unhistorical, renders Christ’s ministry in the heavenly sanctuary as almost meaningless. Death would be a divinely instituted reality if God was involved in an evolutionary process of origin. God, rather than Satan, would have been responsible for the life-death cycle.

11. The Spirit of Prophecy. The writings of Ellen G. White repeatedly testify to a literal six-day creation (Spiritual Gifts, vol. 3, pp. 90-96; letter 7a, 1868) in which God created the world out of nothing (Testimonies for the Church, vol. 8, pp. 258, 259; The Ministry of Healing, pp. 414, 415). “The divine mind and hand have preserved through the ages the record of creation in its purity. It is the word of God alone that gives to us an authentic account of the creation of our world” (Counsels to Parents and Teachers, p. 13). Creation is the basis for the Sabbath ( Patriarchs and Prophets, p. 336; Testimonies to Ministers, pp. 135, 136; letter 26, 1899; letter 7, 1900); and frequent mention is made of the short time that life has been in existence (Spiritual Gifts, vol. 3, p. 92; Testimonies for the Church, vol. 2, p. 172; The Spirit of Prophecy, vol. 4, p. 371; The Great Controversy, pp. 552, 553). An acceptance of progressive creation or theistic evolution would stand in stark contrast to these explicit statements by the Spirit of Prophecy.
12. The Second Coming and the New Creation. The advent of Christ is one of the cherished truths of Adventism. God’s proclamation “Behold, I will create new heavens and a new earth” (Isa. 65:17) has been the hope of thousands throughout the ages. But even if Christ’s second coming were possible in view of millions of years of progressive creation, what hope would there be for a “new” creation? Would God take another 600 million years to create it? ....."

http://www.adventistreview.org/2001-1543/story2.html

Belief in a literal creation week is important to our salvation.

Agreed.

I disagree with the article just a little on the point of "when." I don't think it remains incontrovertibly clear as to "when" the earth was made judging solely by the first verse in the Bible.

Tell me, "when" is "beginning?"

Blessings,

Green Cochoa.

The beginning so far as humans is concerned began about 6,000 years ago. The beginning so far as the planet in its void and formless state is concerned began millions or billions of years ago.