almisami
Even Muhammad made it so that time flowed differently in heaven so that the 7-day myth would be believable.
However I got to say that Muhammad pbuh never wrote the Quran. Allaah made His Creation as He Saw fit and He revealed the Quran (which tells about His Creation) to Muhammad pbuh through the Angel, Gabriel. Muhammad pbuh could not read or write.
And He found you unaware (of the Qur'ân, its legal laws, and Prophethood, etc.) and guided you? (Ad-Duha 93:7)
The seven day idea of the Christian was b/c the Bible said Allaah rested on the seventh day.
This doesnt fit into Islam b/c Allaah states in the Quran He Doesnt Sleep and He Needs no rest.
Allâh! Lâ ilâha illa Huwa (none has the right to be worshipped but He), the Ever Living, the One Who sustains and protects all that exists.
Neither slumber, nor sleep overtake Him. To Him belongs whatever is in the heavens and whatever is on earth. Who is he that can intercede with Him except with His Permission? He knows what happens to them (His creatures) in this world, and what will happen to them in the Hereafter . And they will never compass anything of His Knowledge except that which He wills. His Kursî extends over the heavens and the earth, and He feels no fatigue in guarding and preserving them. And He is the Most High, the Most Great. [This Verse 2:255 is called Ayat-ul-Kursî.] (Al-Baqarah 2:255)
We have our Juma'a on Friday which was the day the Creation was assembled and Adam pbuh was created by Allaah SWT.
Islamically speaking there was creation on Sunday, Monday, Tuesday, Wednesday, Thursday and Friday. Allaah was finished with His Creation before Satuday, the seventh day of the week.
Al-A'raf - 7:54
Indeed your Lord is Allâh, Who created the heavens and the earth in Six Days, and then He Istawâ (rose over) the Throne (really in a manner that suits His Majesty). He brings the night as a cover over the day, seeking it rapidly, and (He created) the sun, the moon, the stars subjected to His Command. Surely, His is the Creation and Commandment. Blessed be Allâh, the Lord of the 'Alamîn (mankind, jinns and all that exists)! (Al-A'raf 7:54)