@alwaysstranger , i got these response and it's so logical to the core and i have also taken understanding from it..
Quran needs to be understood correctly and not literally translated word by word. Its not a text book of science either but provides ample scientific signs to those who actually ponder upon it.
The word yawm which in some places is translated as day, refers to other meanings as well depending upon in which context it is being used. Stages, period, or phases are some other meanings of the same word. Definition of this particular word is also given at another place within the Quran where its says that our one day can be equivalent to many thousand days for Lord Almighty. Point is, it is not our one 24 hour day which is being referred to when time of creation in mentioned.
Quran starts the history of the universe from a phenomenon similar to what was discovered in 1950s, and which we know as the Big Bang.
[21:31] “Do not the disbelievers see that the heavens and the earth were a closed-up mass, then We opened them out?”
Heavens and the earth in this context refers to what we now call the universe. The Arabic words used for the closed up mass (fa-ta-qa) and the opening of it (ra-ta-qa), very clearly refer to a concept of singularity and its well planned opening, not some random blast or explosion. Interestingly, this verse is also a prophecy, that it’d be the disbelievers (atheists) who would one day made this discovery. Observe the words of this verse again.
Then coming back to your question, Quran has mentioned the creation of the universe in six stages, not in six days, and has mentioned it in seven different verses. It has also divided these stages further, for those who want to better narrow down their research on these stages of creation. As I mentioned earlier, the Arabic word yawm, which is translated as day has also other meanings, stages or phases being two of them.
[25:60] He Who created the heavens and the earth and all that is between them in six periods, then He settled Himself on theThrone. The Gracious God! Ask thou then concerning Him one who knows.
[11:8] And He it is Who created the heavens and the earth in six periods
[7:55] Surely, your Lord is Allah Who created the heavens and the earth in six periods; then He settled Himself on the Throne.
[10:4] Verily, your Lord is Allah Who created the heavens and the earth in six periods, then He settled Himself on the Throne; He governs everything.
[32:5] Allah it is Who created the heavens and the earth, and that which is between them, in six periods; then He settled on the Throne. You have no helper or intercessor beside Him. Will you not then reflect?
[50:39] And verily, We created the heavens and the earth and all that is between them in six periods, and no weariness touched Us.
[57:5] He it is Who created the heavens and the earth in six periods, then He settled Himself on the Throne.
There can be a long discussion on various signs, hints and directions which these verses provide. But one thing is for sure, they all refer to six stages of creation and a final and last stage of sitting on the Throne.