“Genesis also says that creation time periods were days, punctuated by light and dark, as in a day.”
Source please (no, really). Are you just referring to “there was evening, and there was morning”?
I’ve found the arguments that say the “days” described can be LITERALLY interpreted as “epochs (varying time periods with a definitive beginning and end)” to be most compelling. This apparently valid interpretation appears to align with what is repeatedly seen in science (as observed today). Why would God want to try and “trick” us on what science repeatedly indicates the age of the universe/earth to be and change the way things “appear” (although I concede he could if he wanted to)? He may not tell us all, but it is not in his character trick us.
Source? Well, none other that Genesis, Chapter 1 of the King James Bible. Read on:
3And God said, Let there be light: and there was light.
4And God saw the light, that it was good: and God divided the light from the darkness.
5And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day.
6And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters.
7And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament: and it was so.
8And God called the firmament Heaven. And the evening and the morning were the second day.
If you read the whole account, it is all given in ‘days’.
You are correct, God will not trick, or LIE, to us. That being the case, His Word must then be true.
Believe science fact, but understand that things such as the Big Bang and evolution are Theories only. Take God at His word. Believe in Him, and lean not to your own understanding.