Jesus My Wisdom said:
The key clue is that "evening and morning" for all the days prior to the creation of the sun. It is dropped after that.
Says who? Where do you see 24 hours in Genesis 1?
You should take note of that. It takes a sun to have an evening and morning, a dawn and dusk.
Ordinarily, yes. So the reason the authors put "evening and morning" was to give that dawn and dusk in the absence of the sun. It is the tie to 24 hour day.
So you figure God rested on Saturday. What do you think he did the next day on Sunday?
Whatever He wanted to. The story stops with God resting on the 7th day.
I bet God was pleased about that. I hope he didn't really observe Sunday. You know, maybe that's why he got mad at us.

For Jews, the Sabbath falls on what we now term "Saturday". Our days of the week are not based on Jewish practice. The very names "Saturday" and "Sunday" come from pagan gods. Saturday is Saturn's day while Sunday is Sun's day. Now, Jesus was crucified on a Friday afternoon. The Sabbath started at sundown that day. That's why they were going to break his legs -- to make sure he was dead so he could be buried before sunset -- since burial is work and forbidden on the Sabbath. What this meant is that Jesus died on Friday afternoon, was dead all day the Sabbath, and rose on the first day of the week -- the third day -- while being dead "only" 36 hours or so.
Now, when Christianity finally acknoweldged that they were not going to convert the Jews and thus began to set up its own traditions they changed the observance of the Sabbath to Sunday in honor of the day Jesus rose from the dead.
You still have not proven a 24 hour day.
JMW
If you mean have I convinced you, then no. But then, it doesn't appear that you are ever going to be convinced. In an earlier post I referenced Exodus 20:11 and a similar verse in Leviticus, where the days of creation are tied to the days of the week. Now, if the days of creation are not 24 hour days, then it makes no sense to do that.
Also, I have found that reference to the seventh day is also "beyom" in Hebrew. "Beyom" or "byvm" in Hebrew is a separate word from "yom" or "yvm". While "yvm" can be an longer than 24 hours, "byvm" means "within a day" or "in the day" and is a period of 24 hours or less.
This is not the best transliteration, but it will do. Here it is "bayom" instead of "beyom", but since written Hebrew has no vowels, picking the vowels in a transliteration is a matter of taste. Genesis 2:2
va.
ye.
khal e.
lo.
him ba.yom ha.
she.
vi.
i me.
lakh.
to a.
sher a.
sa va.
yish.
bot ba.yom ha.
she.
vi.
i mi.
kol-
me.
lakh.
to a.
sher a.
sa:
And on the seventh day God finished His work which He had made; and He rested on the seventh day from all His work which He had made.
So here is textual proof that the seventh day was 24 hours. Now, I suspect that this was done precisely because otherwise the duration of the 7th day is ambiguous since creation is done and there is no signal to start the next day.
Again, this speaks only the the author's
intent and not how long creation actually took. The authors of the creation story Genesis 1:1 -2:4 were writing a theological essay, not a history.