Gen 2:4 introduces a new creation episode. The traditional view takes “in that day” to mean “at the same time,” so that Gen 2:5-9 is a new way of describing the same events of Gen 1. However, “in that day” could very easily be construed in the sense of “right on the heels of” Gen 2:1-3. That is, right after God was done resting He got busy again- this time creating a special human (male) for a special place (presumably for a special purpose -perhaps to elect them as His own children amid the rest of humanity [created in Genesis 1], thereby providing a point of analogy with his later election of Israel). Later in Genesis 2:21-23 God creates a second special human, the female counterpart to the earlier created male human.[/list]
What I'm getting at here, is unless one believes and argues that Genesis 2:4 is the concluding verse all prior rather than the introductory verse to what comes after, then Gen 2:4 doesn't really hold much weight in way of an argument for understanding the days in Genesis 1 as representing long periods of time.
Where we agree... you are correct I do see Genesis 2:4 as the beginning of the section of the narrative that runs from Genesis 2:4 through the end of Genesis 4.
I also see the use of YHWH in this section of Genesis as an indicator that God is interacting with his covenant people beginning with Genesis 2:4 as opposed to generic humanity in Genesis 1:26-28 where Genesis uses the more generic Elohim (I was actually discussing this with my dad yesterday).
Here's where I disagree with your position. Genesis 2:4 is one of the 'toledot' transition verses which as you point out marks the beginning of a new narrative. And the toledot is used to indicate a relationship between the narrative beginning with the toledot and the narrative prior to the toledot. According to John Walton (The Lost World of Adam and Eve - Proposition 7). The toledot is used to indicate that the narrative beginning with Genesis 2:4 is sequential to what happened in Gen 1:1-2:3... not a recapitulation of the events that took place during 'day 6' of Genesis 1.
OK... so what does that have to do with the use of 'day' in Genesis 2:4?
My understanding of the function of the Genesis 2:4 toledot is to basically say... this is what happened when/after God created the heavens and the earth in the previous section.
So even though 'yom' in Gen 2:4 is is part of the beginning of a new narrative, it is still used to look back to the creation of the heavens and the earth which is described in the previous narrative. So It is legitimate to say that the Genesis 2:4 'yom' is used within the context of the creation of the heavens and earth which is described in detail in the previous section (Genesis 1:1-2:3)
Genesis 2:4 is my poster child of an example where yom does not (and cannot) refer to 24 hours within the context of the creation of the heavens and earth.
My other point "and there was evening and there was morning, day x" just points out that that phrase cannot be used assert a 24 hour day. I think the phrase most likely refers to the transition between two days. Something like "day x" came to an end and another day began.
All this to point out that there are a number of meanings for 'yom' in Hebrew, and contrary to the assertions of the YEC tradition there is nothing in the text of Genesis 1 to indicate that a day is 24 hours or a 'regular' day, especially since the word 'yom' is used before the markers for a 'regular' day even become visible on day 4.