“God also said: Let the waters bring forth the creeping creature having life, and the fowl that may fly over the earth under the firmament of heaven. And God created the great whales, and every living and moving creature, which the waters brought forth, according to their kinds, and every winged fowl according to its kind. And God saw that it was good. And he blessed them, saying: Increase and multiply, and fill the waters of the sea: and let the birds be multiplied upon the earth. And the evening and morning were the fifth day.” Genesis 1: 20 - 23
Assume that evolution is essentially correct. You can fit the age of dinosaurs in the fifth day. The first creatures leave the ocean, for land (Waters brought forth). There were living and moving creatures, and great whales. Dinosaurs? Then the day ends with winged fowls, he blesses the birds, that they could multiply on the earth. This could be the end of the dinosaurs, which evolved into … birds! So this “day” was a long age that started with the first creature to crawl onto land with legs, and ends with the dinosaurs becoming birds. Then the next age is ready for mammals and man.