For God, according to the heavenly tablets, a thousands years are like a day. But in fact, the days of creation were exactly 24 hours. Because if you look more closely, you will see that it is written at the end of each day of creation:It's a crude attempt at concluding the Earth's age by going through the family trees presented in the Bible from Adam to Christ. It actually tends to produce a range between 6,000 - 10,000 years old. But, be as that may, many (including many fundamentalist/evangelical types) will state that must assume that the 7 Days of Creation would have been the 24-hour days we know, but we don't know what a day to god is. This leads to a group that doesn't really care, rejecting YEC and potentially scientific explanations. However, interpreting the days of creation to be longer than the days we know--entire periods of time and history--this gives rise to beliefs such as Old Earth Creationism, which does include evolution, however views it as being guided by god (and this view is made possible when a day is viewed as billions of years and then what we see is a gradual appearance of everything, including biodiversity).
"And it was evening and it was morning; the ? day". The logical conclusion of this is that the days of creation were indeed 24 hours each.
But there is a reason for all this, because of course God, if he wanted to, could have created the world in less than 1 second. But he had it done that way, as a sign of time and especially as a sign of the Sabbath.