According to Bible, the revolves(day length calculation) is started with the creation of the first light - 1.In the beginning, God created the heavens and the earth. 2.The earth was without form and void, and darkness was over the face of the deep. And the Spirit of God was hovering over the face of the waters. 3.And God said, Let there be light, and there was light. 4.And God saw that the light was good. And God 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 - Genesis 1:1-5

there are many light sources in this Galaxy Like Sun, Moon, and Stars etc., but the only spinning light source is Milky way galaxy itself, so its very clear, what God created in the beginning is galaxy, and the 6 day creation is based on the revolution time of Milky way galaxy itself, so one day in God's creation account is 240 Million Earth years, which is equivalent to 87,600,000,000 earth days, or 2,102,400,000,000 earth hours.

And Bible is very clear that God created Sun and Moon on the 4th day, that means, the first three days calculation is not based on the Sun and Earth, but based on the Milky way galaxy revolution time - 14.And God said, Let there be lights in the expanse of the heavens to separate the day from the night. 15.And let them be for signs and for seasons, and for days and years, and let them be lights in the expanse of the heavens to give light upon the earth. And it was so. 16.And God made the two great lights, the greater light to rule the day and the lesser light to rule the night, and the stars. 17.And God set them in the expanse of the heavens to give light on the earth, 18.to rule over the day and over the night, and to separate the light from the darkness. And God saw that it was good. 19.And there was evening and there was morning, the fourth day - Genesis 1:14-19

Generation of Milky way Galaxy

in God's creation account, one of the Most important words is "generation", sadly the word "generation" was removed from many Bible translations, actually the word "generation" tells that all the planetary bodies like Sun, Moon, and the planets including the Earth that we live are born from the Milky way galaxy - These are the generations of the heavens and the earth(Galaxies) when they were created, in the day that the Lord God made the earth and the heavens(Planetary bodies) - Genesis 2:4

Here the word "Heavens and Earth" is pointing to Galaxies that are created in the Beginning(before time begins), and the word "Earth and the Heavens" are referring to planetary bodies (Earth, other planets, Sun, Moon, Stars etc.) that are created inside of the Milky way Galaxy, and these planetary bodies created as the Milky way Galaxy revolves, that was the reason Bible says that "Heavens and Earth" are created in the Beginning, and "Earth and the Heavens" are created in the Day.

How many revolution the Milky way Galaxy completed?

Milky way Galaxy completed has 6 spins so for, and its in 7th spin now, that means Milky way Galaxy in action for 1.44 billion years (6 X 240 million years) with the particles that are created before the time begins.

And the Bible never said that 7th day is completed, that was the reason everyone still call it as "God's 6 days creation", and we are living in the 7th day(revolution) of Milky way Galaxy - 2.And on the seventh day God finished his work that he had done, and he rested on the seventh day from all his work that he had done. 3.So God blessed the seventh day and made it holy, because on it God rested from all his work that he had done in creation - Genesis 2:2-3

Two types of Heaven: There are two types of Heavens(Empty Spaces) mentioned in the Bible, and Nehemiah also wrote about that - You are the Lord, you alone. You have made heaven, the heaven of heavens, with all their host, the earth and all that is on it - Nehemiah 9:6a.

And according to Bible the first heaven(mother heaven) was created for Galaxies to survive - In the beginning, God created the heavens and the earth - Genesis 1:1

And the another heaven(child heaven) was created within the Galaxy where our earth, other planets, Sun, Moon, Stars lives, this child heaven was created in the 2nd revolution the Milky way galaxy - And God called the expanse heaven. And there was evening and there was morning, the second day - Genesis 1:8

Two types of Earth: There are two types of Earth with similar attributes, first one is the Milky was Galaxy(mother earth) which spins on its own axis and got created before time begins - In the beginning, God created the heavens and the earth - Genesis 1:1

And the second Earth(child earth), the planet that we live got created on the third revolution of the Milky was Galaxy - 9.And God said, “Let the waters under the heavens be gathered together into one place, and let the dry land appear.” And it was so. 10.God called the dry land Earth, and the waters that were gathered together he called Seas. And God saw that it was good - Genesis 1:9-10

Two types of waters: There are two types of water bodies mentioned in the Bible, first one is the melted Milky way galaxy, when it got melted by the enormous heat produced by the Galactic Center or Black hole - 6.And God said, “Let there be an expanse in the midst of the waters, and let it separate the waters from the waters.” 7.And God made the expanse and separated the waters that were under the expanse from the waters that were above the expanse. And it was so - Genesis 1:6-7

And as the melted galaxy keep expanding, God created the Empty spaces inside the Milky way galaxy, and as the temperature got dropped at the surface area, the Earth was formed with second type of water body, that is our Ocean - 9.And God said, “Let the waters under the heavens be gathered together into one place, and let the dry land appear.” And it was so. 10.God called the dry land Earth, and the waters that were gathered together he called Seas. And God saw that it was good - Genesis 1:9-10

Two types of Lights - There are two types of lights mentioned in the Bible, the first light is at the center of Milky way galaxy(Galactic Center), which made the Milky way galaxy to spin, and also the beginning of time - 3.And God said, Let there be light, and there was light. 4.And God saw that the light was good. And God 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 - Genesis 1:3-5 

 
And second set of lights are Sun, Moon and Stars that are created at the 4th spin of the Milky way galaxy - And God said, Let there be lights in the expanse of the heavens to separate the day from the night - Genesis 1:14

Two types of Days: There are two types of "Day" mentioned in the Bible, The first one is "Galaxy Day" which is around 240 Million Years, and according to Bible the Galactic Center produces two types of lights/radiations, so half of the Galaxy would experience Morning, and half of the Galaxy would experience Evening, the differences are yet to be discovered, and now our Earth is travelling on the evening side of the Milky way Galaxy.

The another type of Day is "Earth Day" which is 24 Hours, Bibles says that God created Sun and Moon to rule the day and night, that means the Earth was ruled by Galactic Center light, but as the Earth is moving away from the Galactic Center, the Sun became a ruler of the Earth, and the Sun also gives seasons and yearly calculations to the earth - And God said, Let there be lights in the expanse of the heavens to separate the day from the night. And let them be for signs and for seasons, and for days and years - Genesis 1:14

In the Beginning (Before 1.44 Billion Years)

In the Beginning God created the empty spaces and the Galaxies, this picture is just an idea how the Galaxy could be before its start emitting light, because we cannot see the Galaxy until its start spinning, and modern day science calls this as "unseen matter" - 1.In the beginning, God created the heavens and the earth. 2.The earth was without form and void, and darkness was over the face of the deep. And the Spirit of God was hovering over the face of the waters - Genesis 1:1-2

Why God created so many Galaxies?

There was a wonderful reason for that, Actually we cannot see the full structure of our Milky way Galaxy as we live inside of it, but we can see other Galaxies and by studying them we can understand the structure, how it spins, and how Planets are getting created.

Day #1 (1st spin of Milky way) from 1.2 - 1.44 billion years ago

3.And God said, Let there be light, and there was light. 4.And God saw that the light was good. And God 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 - Genesis 1:3-5

When God said, Let there be light, the central part of the Galaxy(Galactic Center) started emitting the light, and became a rotational center for Galaxy to spin, and the extreme high temperature (around one-millionth of a degree above absolute zero) melted the whole Milky way galaxy - He uttered His voice, the earth melted - Psalm 46:6

Day #2 (2nd spin of Milky way) from 960 - 1200 million years ago

6.And God said, Let there be an expanse in the midst of the waters, and let it separate the waters from the waters. 7.And God made the expanse and separated the waters that were under the expanse from the waters that were above the expanse. And it was so. 8.And God called the expanse Heaven. And there was evening and there was morning, the second day - Genesis 1:6-8

Inside the melted Galaxy, God created the empty spaces for the planetary bodies(Earth, Sun, Moon, etc.) to survive, and as the melted Galaxy continue expanding, it got a new circular shape - When He established the heavens, I was there; when He inscribed a circle on the face of the deep - Proverbs 8:27

Day #3 (3rd spin of Milky way)  from 720 - 960 million years ago

9.And God said, Let the waters under the heavens be gathered together into one place, and let the dry land appear. And it was so. 10.God called the dry land Earth, and the waters that were gathered together he called Seas. And God saw that it was good - Genesis 1:9-10

As the melted galaxy spreading away from the Galactic Center, there was a temperature drop in far areas and earth got created, and this is how the Galaxy gave birth to the planet earth - The waters become hard like stone, and the face of the deep is frozen - Job 38:30

On the same 3rd revolution of the Milky way Galaxy, the earth also started receiving the perfect temperature from the Galactic Center for plants and trees to grow, and also the earth was experiencing the day & night as it revolves in its own axis - 11.And God said, "Let the earth sprout vegetation, plants yielding seed, and fruit trees bearing fruit in which is their seed, each according to its kind, on the earth". And it was so. 12.The earth brought forth vegetation, plants yielding seed according to their own kinds, and trees bearing fruit in which is their seed, each according to its kind. And God saw that it was good. 13.And there was evening and there was morning, the third day - Genesis 1:11-13

So when God created the plants, all the plants were survived by the light of Galactic Center, not by the Sun, and God preserved these trees as coals and petrified wood, and these are still an evident for God's amazing creation. 

Day #4 (4th spin of Milky way) from 480 - 720 million years ago

14.And God said, “Let there be lights in the expanse of the heavens to separate the day from the night. And let them be for signs and for seasons, and for days and years, 15.and let them be lights in the expanse of the heavens to give light upon the earth.” And it was so. 16.And God made the two great lights, the greater light to rule the day and the lesser light to rule the night, and the stars. 17.And God set them in the expanse of the heavens to give light on the earth, 18.to rule over the day and over the night, and to separate the light from the darkness. And God saw that it was good. 19.And there was evening and there was morning, the fourth day - Genesis 1:14-19 

As the earth continued moving away from the Galactic Center, Lord Jesus Christ created the Sun, Moon and Stars to maintain the temperature of the earth, and now, the earth slowly started forgetting about Galactic Center from where she used to receive the light, and adapted into her new family of Sun, Moon and Stars, but this transition took 240 million years.

Day #5 (5th spin of Milky way) from 240 - 480 million years ago

20.And God said, “Let the waters swarm with swarms of living creatures, And let birds fly above the earth across the expanse of the heavens.” 21.So God created the great sea creatures and every living creature that moves, with which the waters swarm, according to their kinds, and every winged bird according to its kind. And God saw that it was good. 22.And God blessed them, saying, “Be fruitful and multiply and fill the waters in the seas, and let birds multiply on the earth.” 23.And there was evening and there was morning, the fifth day - Genesis 1:20-23

After creation of Sun and Moon, God created the sea creatures, and then God created the Birds, that was the reason the marine fossils are the oldest fossils ever been found, and the next oldest fossils are belongs to Birds.

Day 6# (6th spin of Milky way) from 6000 BC - 240 million years ago

24.And God said, “Let the earth bring forth living creatures according to their kinds, livestock and creeping things and beasts of the earth according to their kinds.” And it was so. 25.And God made the beasts of the earth according to their kinds and the livestock according to their kinds, and everything that creeps on the ground according to its kind. And God saw that it was good - Genesis 1:24-25

So, at the sixth spin of the Milky way galaxy, God created all types of animals, and no doubt that the animal fossils exactly fits into this timeframe, even the Dinosaurs or Mesozoic era falls in this time timeframe.

The science doesn't know how many spins the Galaxy made so for? But bible has the answer for this.

The science doesn't know both Galactic Center and Sun produces similar type of energy which could grow plants, But bible has this information.

The science doesn't know the plants of the earth once survived by the light of the Galactic Center, But bible has this information.

The science doesn't know that the Galactic Center produces two types of Lights (morning and evening), But bible has this information.