score:8
As mentioned in the comments the LDS church believes:
Latter-day Saints have additional information that allows a third view—that each “day” of the Creation was of unspecified duration and that the Creation of the earth took place during an unknown length of time. Abraham stresses that day is synonymous with time. For example, Abraham 4:8 summarizes the second creative period by stating that “this was the second time that they called night and day.” This usage is consistent with ancient Hebrew. The Hebrew word YOM, often translated day, can also mean “time” or “period.” In other words, the term translated day in Genesis could be appropriately read as “period.”1
See also:
A third theory says that the word day refers to a period of an undetermined length of time, thus suggesting an era. The word is still used in that sense in such phrases as “in the day of the dinosaurs.” The Hebrew word for day used in the creation account can be translated as “day” in the literal sense, but it can also be used in the sense of an indeterminate length of time (see Genesis 40:4, where day is translated as “a season”; Judges 11:4, where a form of day is translated as “in the process of time”; see also Holladay, Hebrew and Aramaic Lexicon of the Old Testament, pp. 130–31). Abraham says that the Gods called the creation periods days (see Abraham 4:5, 8).2
1 https://www.lds.org/liahona/1998/03/i-have-a-question/the-length-of-creation?lang=eng