Fussilat · 41:12

12. Then Allah completed the creation of the heavens in two days: Thursday and Friday. With that, the creation of the heavens and the earth was completed in six days. Allah inspired in every heaven whatever He would decree concerning it and whatever obedience and worship He would command. Allah also decorated the nearest heaven with stars, and protected it from the satans’ eavesdropping. All that is the decree of the Almighty who no one can overcome, and who is all aware of His creation.