I ran into an interesting article by Sterchi in JETS who argues based on the Hebrew grammar the 7 days are NOT in chronological but theological order. His argument (of which below is a very small snippet) is pretty interesting. It certainly makes more sense of the evening & morning being time markers for days 1-3 before the sun and moon are made on day 4. Not such a good read for literalists who dislike Bible scholarship.
“Mark Throntveit suggests that this structural relationship with some textual hints points to the fact that the sequence of days is not chronologically ordered at all. This is a quantum leap. It is one thing to suggest that a factual or historical account has a literary structure. It is something else to say that such an account is not chronologically ordered even though it is saturated with chronological terminology. It is essential, then, that the text be scrutinized for any and all clues about chronology or its absence.
The pertinent phrases in the MT read yôm ʾeḥād (Gen 1:5), yôm s̆ēnî (1:8), yôm s̆ĕlîs̆î (1:13), yôm rĕbîʿî (1:19), yôm ḥămîs̆î(1:23), yôm has̆s̆is̆s̆î (1:31), bayyôm has̆s̆ĕbîʿî (2:2b). One observation I would like to point out is that the noun yôm (“day”) does not have the definite article with the possible exception of day seven, bayyôm has̆s̆ĕbîʿî. A second observation is the absence of the definite article on the numbers ʾeḥād through hAmîsî (“one” through “fifth”), while the article is present on has̆s̆is̆s̆î and has̆s̆ĕbîʿî (“sixth,” “seventh”). The third observation is the use of cardinal and ordinal numbers in the sequence: ʾeḥād (the cardinal “one”), s̆ēnî through s̆ĕbîʿî (the ordinals “second” through “seventh”). One final observation is that the critical apparatus of BHS shows no textual variation concerning these observations. Let us examine each observation in more detail.
The pattern all these days share is that the noun yôm is followed by its number. Each occurrence of yôm is without the definite article. The missing article may be an attempt to avoid its original function as a demonstrative pronoun. When hayyôm refers to a particular calendar day or solar day (21:26) or to a particular but unspecified period of time (19:37) it means “today.” Therefore the absence of the article may not indicate that the noun is in-definite. In fact the number that modifies yôm can determine whether it is definite or indefinite.
So what do the numbers tell us? Since the first five numbers have no definite article, yôm is likely to be indefinite for the first five days. But this can only be said with reasonable certainty for days two through five. It seems possible that the first day is definite because of the nature of ʾeḥād and that yôm is determined by it.”Sterchi, D. A. (1996). Does Genesis 1 Provide a Chronological Sequence? Journal of the Evangelical Theological Society, 39:4, (December 1996) pages 530–531.
So much interesting stuff out there to read – if only people would stop trying to threaten those who enjoy reading and exploring (looking at you right now northern Adelaide ecclesias!)