Looking at Genesis one, the Partial- Creation approach has six literal days where gaps of time exist to make for a old earth view (progressive creationism). The Gap theory, supported by Thomas Chalmers and C.I. Scofield, has the original creation existing in verse one. The Devil disrupts God's creation in verse two and the literal six days of creation begin on verse three. Genesis 1:1 would account for a long period of time before the six literal days of creation. The Hesitation theory has a long period of time in Genesis 1:1 again, followed by a literal six days of creation. This view is supported by William Stokes and Gorman Gray. The Intermittent view, supported by J. Barton Payne and Robert C. Newman. The intermittent view has six literal 24 hour days of creation with long gaps of time in between the creation days.
I do not lean toward any of these views, but if I had to chose the one I believe best matches Scripture and what we know scientifically, I would have to go with the Intermittent view. I personally hold to a Long-Day approach to creation which will be discussed on the next post.