In all my searching and discussing the issue of the interpretation of the days of creation in Genesis 1, Google directed me to a statement from Westminster Theological Seminary declaring the results of their research into the history of how this issue has been treated by the leaders of the Augustinian and Reformed traditions going all the way back to Augustine himself. The statement is called, “Westminster Theological Seminary and the Days of Creation.“
The discussion among Presbyterians revolves around the reasons the Westminster Divines selected the language they did in when they framed the chapter on Creation in the Westminster Confession of Faith. The phrase in question will be highlighted in the following citation:
I. It pleased God the Father, Son, and Holy Ghost, for the manifestation of the glory of His eternal power, wisdom, and goodness, in the beginning, to create, or make of nothing, the world, and all things therein whether visible or invisible, in the space of six days; and all very good.
The question is raised as to why the wording “in the space of six days.” Why not simply “in six days”? The statement explains:
“The paraphrase view is doubtful because if the Standards had intended simply to utilize biblical language, “in six days” would have sufficed and been a more natural choice. The words “the space of,” as the other view above recognizes, seem deliberately chosen as an interpretive or clarifying addition that functions both to affirm and to exclude or negate.
To make the long story short, the statement concludes that the divines intended to exclude Augustine’s view that God created everything instantaneously inspiring the six days, as Calvin described the view (which he did not hold), “for the mere purpose of conveying instruction.” You can read more about this discussion in the statement itself. You can link to it from the title above, and I have also added a link to the page on my “Recommended Sites” page for future reference.
Finally, here’s a quote that sums up the entire issue as they see it. I find it rather helpful:
With Augustine and E. J. Young, the revered teacher of our senior faculty members, we recognize that the exegetical question of the length of the days of Genesis 1 may be an issue which cannot be, and therefore is not intended by God to be, answered in dogmatic terms. To insist that it must comes dangerously close to demanding from God revelation which he has not been pleased to bestow upon us, and responding to a threat to the biblical world view with weapons that are not crafted from the words which have proceeded out of the mouth of God.