Frankly, arguing whether Yom is a literal 24 day is rather silly. Even if you allow days 4-7 to be indeterminate periods of time, you've got lots of other aspects of the Genesis creation storeis that conflict with science. For instance, the order in which creatures appear contradicts the fossil record. Land animals preceded birds, not the other way around. Plants could not live without the sun. Etc, etc, etc.
The only rational interpretation of Genesis 1-2 is that they allegories designed to convey certain historical truths important to salvation. The details are unimportant and not meant to be taken seriously, but are either filler, to keep the story interesting, or symbols. The fact that some details contradict each other in places ought to clue the reader into this obvious fact.
Another way of looking at the text is given by Origen, (cut & paste from class notes, errors mine)
Origen of Alexandria (ca. 185-254), held that one often came across what he called impossibilities in the text, impossibilities of various sorts: mythological creatures, historical impossibilities, lapses of logic, etc. His theory was that the sacred authors, inspired by the Holy Spirit, placed these intentionally into the text so that the spiritual character or inner meaning of the text could show through. He comments:
Divine Wisdom has arranged for there to be certain stumbling blocks or interruptions of the narrative meaning, by inserting in its midst certain impossibilities and contradictions, so that the very interpretation of the narrative might oppose the reader, as it were, with certain obstacles thrown in the way. By them Wisdom denies a way and an access to the common understanding, and when we are shut out and hurled back, it calls us back to the beginning of another way, so that by gaining a higher and loftier road through entering a narrow footpath it may open for us the immense breadth of divine knowledge.
Or again, Origen comments that by means of the impossibilities sprinkled into the narrative, the Holy Spirit acts to turn and call back the mind of the reader to the examination of the inner meaning of the narrative (On First Principles 4.2.9)."
That's not correct. Kaiser was aluding to different possibilities, but Ross maintains that the days were long periods of time. See his book "A Matter of Days."
In the young-earth view you have plants appearing before the Sun, but the OE view recognizes that in the early Earth that the Sun was hidden by the clouded atmosphere. This matchs percisely with Genesis, especially when the Hebrew is properly rendered.
The sequence of animals is also correct when one correctly considers the Hebrew meaning(s). Most people don't realize that ancient Hebrew had limited vocabulary and that most words had multiple meanings. Many translaters translated the words to what fit their view. Newer translations are closer to the mark. These issues also make the YEC "literal" view laughable, because it's not literal at all.
So there's no need to resort to allegories to explain away Genesis. As Ross explains in his book "The Genesis Question," Genesis matches precisely with science. Hence Genesis becomes a powerful evidence for the Bible's authenticity.