Day-Age creationism, a type of Old Earth creationism, is an interpretation of the creation accounts found in Genesis. It holds that the six days referred to in the Genesis account of creation are not ordinary 24-hour days, but rather are much longer periods (of thousands or millions of years). Proponents of the Day-Age Theory can be found among theistic evolutionists (who accept the scientific consensus on evolution) and progressive creationists (who reject it).
The Day-Age Theory tries to reconcile the opposite views by arguing that the Creation “days” were not ordinary 24-hour days, but actually lasted for long periods of time. Genesis can then be read as a summary of modern science, simplified for the benefit of pre-scientific humans.
The Old-Earth figurative view can be traced back at least to Saint Augustine in the 5th Century who pointed out, in “De Genesi ad Litteram”, that the “days” in Genesis could not be literal days, if only because Genesis itself tells us that the sun was not made until the fourth “day”.
8.11.2 Interpretation of Genesis
Day-Age creationists differ from young Earth creationists in how they interpret a number of crucial Hebrew words in Genesis, and thus how they interpret the genealogies and creation account contained in it.
They point out that the Hebrew words for father (‘ab) and son (ben) can also mean forefather and descendent, respectively. This, they argue, renders genealogically-based dating of the Creation, such as the Ussher chronology, to be inaccurate.