1) The length of the Day is not always 24 hours in the Quran. It varies by context. For example, it says one Day on the Day of Judgement is 50,000 years and one Day in Heaven is 1000 years. In this context, One Day corresponds to 100 million years where each Day is a milestone marker of creation. Six Days of creation of the heavens and the earth are the phases or the stages in which the Solar system, the Earth's Atmosphere [the Heavens], and the Earth were created. This process followed from the blast of the Solar Wind as a result of nuclear fusion in the Solar Nebula which created the Sun 4.6 billion years ago.
Yes days were not always 24 hrs but the earlier you go the day length reduces (for example 1 million years ago it would be may be 23 hours)
So 1000 years , 50,000 years, 100 Million years long day is bull shit
Even if we assume 100 Million years day, number do-not add up, Universe is 13.8 Billion years old, Earth is 4.6 Billion years old
A 10 grade school boy of modern time Knows how to set context, how to address and audience in written / oral way, A super being and a super book if true cannot be so vague (1 day = 24 hrs, 1 day = 1000 years, 1 day = 50,000 years, I am sure tomorrow some molvi will come any say Allah's one day was 2.3 Billion years so 6 days = 13.8 billion yet proving universion creation true according to quran )
"2) I did not read such a thing in the Quran."
Read again
3) "This is in Hadith, not in the QuranWhen I interpret verses I do it only on the basis of the Quran. Quran calls itself complete and I respect that."
Quran is incomplete and is incomprehensible without hadith, tell me how to perform Namaz according to quran (on knees, or standing or on one leg, or lying down, which verses , what times not thing is mentioned, and the same is true for all aspects of Islam)
4) Your interpretation is wrong, how can you separate some thing which was not there (not in same time frame),
Universe was created 13.8 billion years ago, there was not earth for next 9 billion years,
5) I will prefer what geologists have to say instead of some random youtube videos