It is argued that the Arabic word translated here means periods of time rather than days. If this is the case then we do not know how long each period of time is so the length of each period is. If the periods of time are the same then the Earth would have existed for at least 50% of the life of the universe. The same word is used elsewhere in the Quran to literally mean an Earth day It is for these reasons that mentioning the periods of time is irrelevant and unnecessary, and makes the Quran resemble the incorrect creation story of Genesis.
This verse is often used to try to claim that the Quran states the Earth is a sphere, however the words used could just as easily apply to a geocentric universe where the day and night wrap because the Sun orbits the Earth; especially as the same verse also mentions the Sun running/moving for a fixed term.
The verses describe the creation order of the Earth and heavens in the same order as Genesis, which has the Earth and vegetation (sustenance) created before the heavens and the stars, and has the Earth fully formed before the heavens. All of which is scientifically known to be incorrect.
This verse could be interpreted as saying that a journey continued until the place of the rising sun was reached. This implies a flat Earth where the sun orbits the Earth and sets in a specific place each night.
This verse mirrors some erroneous ancient beliefs that the night is a physical entity that is able to block out our vision of the Sun.