1 In the beginning God created the heavens and the earth. (insert hundreds, or thousands, or millions or maybe billions of years) 2 Now the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters. 3 And God said, “Let there be light,” and there was light. 4 God saw that the light was good, and he separated the light from the darkness. 5 God called the light “day,” and the darkness he called “night.” And there was evening, and there was morning—the first day......
The text would indicate that the time frame for each day is equal for the six days. Whatever period of time you enter, the interval would need to be constant. A constant interval is contrary to evolutionary theory.