The word used in the Hebrew scriptures which is translated as 'day', yom , has indeed a variety of meanings according to context. Included in these is an indefinite period of time. When it is qualified by 'evening and morning' it can only mean a day of 24 hours as we know it today. This is even acknowledge by those who do not believe the account to be true, and re-interpret it due to their beliefs, to be the original and intended meaning. The days, in their intended meaning are not symbolic but literal, even though they are given a different meaning due to extra-Biblical beliefs about origins.
Christians believe that the world was created by the word of God. Since God is almighty He can use any means He wishes to bring something into being such as the forming of Adam from the earth, although Adam, like all other humans, was obviously much more than earth. Basically God spoke and it happened. Although obviously all the incredible detail such as in the DNA sequence, for example, was in the mind of God when He spoke, since, if He had to spell out every detail, the creation would not be finished yet and we would not be here. (this latter thought being the personal view of the poster of this answer - there probably being a number of different Christian views as to what 'the word of God' in relation to the creation actually means).
3Through faith we understand that the worlds were framed by the word of God, so that things which are seen were not made of things which do appear.
2The same was in the beginning with God.
3All things were made by him; and without him was not any thing made that was made.
Heb 1:1-3 "God, who at sundry times and in divers manners spoke in time past to the fathers by the prophets, Has in these last days spoken to us by His Son, whom He has appointed heir of all things, by whom also He made the worlds; Who being the brightness of His glory, and the express image of His person, and upholding all things by the word of His power, when He had by Himself made purification of our sins, sat down on the right hand of the Majesty on high;"
Heb 1:10-12 "And, You, Lord, in the beginning have laid the foundation of the earth: and the heavens are the works of Your hands. They shall perish; but You remain: and they all shall become old as does a garment; And as a vesture will You fold them up, and they shall be changed; but You are the same, and Your years shall not fail."
Heaven and Earth, formless and unfilled and dark and deep and watery, with the Spirit of God moving; to the left and right, to the top and bottom, to the front and back, and then residing in the centre; the Love In God's Harmonic Tones produced LIGHT; it was good, and with its division, then came night; and the evening and the morning were the first day ever, as intergalactic dimensional duration began with the first seven days of the space/time continuum.
- Light, with Day and Night spoken into being
- Sky spoken into being
- Land, Sea, and Plants spoken into being
- Sun, Moon, and Stars spoken into being
- Animals of the sea and air spoken into being
- Animals of the land, and Man in the image of God spoken into being
- Rest taken by God at the end of a very creative week
How long is a day? For us, one complete rotation of our planet counts as a day.
How loudly did God speak? An immeasurable volume.
While the bible uses the term "7 days" to explain the time period Jehovah used to create the earth, these are simply symbolic days. The Hebrew word translated 'day' has a variety of meanings, including 'a long time; the time covering an extraordinary event.' The term used allows for the thought that each 'day' could have been thousands of years in length.
*All information comes from a book called "Reasoning from the Scriptures," published in 1989 by the Watchtower Bible and Tract Society of New York, Inc.
As has already been stated we do not know just how long God took to gather all of the matter together, not that it matters. The fact that God was able to command the intelligence which matter had, to form the earth and the seas is in accord with gospel principles.
According to Genesis, the world was created by the Word of God. The words "And God said let there be..." are repeated throughout the general account in Genesis chapter 1. Thus, the God who can call things into existence merely by speaking them (obviously as an expression of His thought and intention of how they were to be, with all their incredibly complex constituent parts, DNA etc.) is indeed almighty and to be both feared and praised.
God, who existed before all else, created the heavens and the earth and all that dwell therein. Here is the scripture for the creation story from the book of Genesis in the Bible: 1 In the beginning God created the heavens and the earth. 2 Now the earth was [a] formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters. 3 And God said, "Let there be light," and there was light. 4 God saw that the light was good, and He separated the light from the darkness. 5 God called the light "day," and the darkness he called "night." And there was evening, and there was morning-the first day. 6 And God said, "Let there be an expanse between the waters to separate water from water." 7 So God made the expanse and separated the water under the expanse from the water above it. And it was so. 8 God called the expanse "sky." And there was evening, and there was morning-the second day. 9 And God said, "Let the water under the sky be gathered to one place, and let dry ground appear." And it was so. 10 God called the dry ground "land," and the gathered waters he called "seas." And God saw that it was good. 11 Then God said, "Let the land produce vegetation: seed-bearing plants and trees on the land that bear fruit with seed in it, according to their various kinds." And it was so. 12 The land produced vegetation: plants bearing seed according to their kinds and trees bearing fruit with seed in it according to their kinds. And God saw that it was good. 13 And there was evening, and there was morning-the third day. 14 And God said, "Let there be lights in the expanse of the sky to separate the day from the night, and let them serve as signs to mark seasons and days and years, 15 and let them be lights in the expanse of the sky to give light on the earth." And it was so. 16 God made two great lights-the greater light to govern the day and the lesser light to govern the night. He also made the stars. 17 God set them in the expanse of the sky to give light on the earth, 18 to govern the day and the night, and to separate light from darkness. And God saw that it was good. 19 And there was evening, and there was morning-the fourth day. 20 And God said, "Let the water teem with living creatures, and let birds fly above the earth across the expanse of the sky." 21 So God created the great creatures of the sea and every living and moving thing with which the water teems, according to their kinds, and every winged bird according to its kind. And God saw that it was good. 22 God blessed them and said, "Be fruitful and increase in number and fill the water in the seas, and let the birds increase on the earth." 23 And there was evening, and there was morning-the fifth day. 24 And God said, "Let the land produce living creatures according to their kinds: livestock, creatures that move along the ground, and wild animals, each according to its kind." And it was so. 25 God made the wild animals according to their kinds, the livestock according to their kinds, and all the creatures that move along the ground according to their kinds. And God saw that it was good. 26 Then God said, "Let us make man in our image, in our likeness, and let them rule over the fish of the sea and the birds of the air, over the livestock, over all the earth, [b] and over all the creatures that move along the ground." 27 So God created man in his own image,
in the image of God he created him;
male and female he created them. 28 God blessed them and said to them, "Be fruitful and increase in number; fill the earth and subdue it. Rule over the fish of the sea and the birds of the air and over every living creature that moves on the ground." 29 Then God said, "I give you every seed-bearing plant on the face of the whole earth and every tree that has fruit with seed in it. They will be yours for food. 30 And to all the beasts of the earth and all the birds of the air and all the creatures that move on the ground-everything that has the breath of life in it-I give every green plant for food." And it was so. 31 God saw all that he had made, and it was very good. And there was evening, and there was morning-the sixth day.
1 Thus the heavens and the earth were completed in all their vast array. 2 By the seventh day God had finished the work he had been doing; so on the seventh day he rested [a] from all his work. 3 And God blessed the seventh day and made it holy, because on it he rested from all the work of creating that he had done.