Does the OPC have a statement or decision regarding the length of the days of creation?
The OPC, as a denomination, has no statement or decision regarding the length of the days of creation. Though General Assembly denied the appeal of a ruling elder who taught the animal ancestry of Adam (determining that such teaching was contrary to the Westminster Confession of Faith), it has thus far had no judicial case with regard to the length of the days of creation, and therefore has rendered no ruling on the matter. OPC ministers and elders are divided on the issue. Those who hold to literal 24-hour days appeal to the words "in the space of" in Shorter Catechism question 9 ("The work of creation is God's making all things of nothing, by the word of his power, in the space of six days, and all very good"). On the other hand, those who hold to the day-age theory or framework hypothesis argue that the biblical text is inconclusive as to the length of the days, and the phrase "in the space of" is not determinative. The OPC is a confessional church, and therefore the Confession, Larger and Shorter Catechisms must always be the standard by which to determine an officer's orthodoxy. Unless it is determined by a judicial ruling that our doctrinal standards teach a particular position, there must be latitude in this area.
The Following is the opening statement of the PCA Report on the Creation question. The rest of the report can be found here.
REPORT OF THE CREATION STUDY COMMITTEE
We thank our God for the blessings of the last two years. We have profited personally and together by the study of God’s Word, discussion and hard work together.
We have found a profound unity among ourselves on the issues of vital importance to our Reformed testimony. We believe that the Scriptures, and hence Genesis 1-3, are the inerrant word of God. We affirm that Genesis 1-3 is a coherent account from the hand of Moses. We believe that history, not myth, is the proper category for describing these chapters; and furthermore that their history is true. In these chapters we find the record of God’s creation of the heavens and the earth ex nihilo; of the special creation of Adam and Eve as actual human beings, the parents of all humanity (hence they are not the products of evolution from lower forms of life). We further find the account of an historical fall, that brought all humanity into an estate of sin and misery, and of God’s sure promise of a Redeemer. Because the Bible is the word of the Creator and Governor of all there is, it is right for us to find it speaking authoritatively to matters studied by historical and scientific research. We also believe that acceptance of, say, non-geocentric astronomy is consistent with full submission to Biblical authority. We recognize that a naturalistic worldview and true Christian faith are impossible to reconcile, and gladly take our stand with Biblical supernaturalism.
The Committee has been unable to come to unanimity over the nature and duration of the creation days. Nevertheless, our goal has been to enhance the unity, integrity, faithfulness and proclamation of the Church. Therefore we are presenting a unanimous report with the understanding that the members hold to different exegetical viewpoints. As to the rest we are at one. It is our hope and prayer that the Church at large can join us in a principled, Biblical recognition of both the unity and diversity we have regarding this doctrine, and that all are seeking properly to understand biblical revelation. It is our earnest desire not to see our beloved church divide over this issue.