Question: "Does Genesis chapter 1 mean literal 24-hour days?"

Answer: A careful examination of the Hebrew word for “day” and the context in which it appears in Genesis will lead to the conclusion that “day” means a literal, 24-hour period of time. The Hebrew word yom translated into the English "day" can mean more than one thing. It can refer to the 24-hour period of time that it takes for the earth to rotate on its axis (i.e. "there are 24 hours in a day"). It can refer to the period of daylight between dawn and dusk (i.e. "it gets pretty hot during the day but it cools down a bit at night"). And it can refer to an unspecified period of time (i.e. "back in my Grandfather's day..."). Likewise, the Hebrew word "yom" (which translates into the English "day") can mean more than one thing. It is used to refer to a 24-hour period in Genesis 7:11. It is used to refer to the period of daylight between dawn and dusk in Genesis 1:16. And it is used to refer to an unspecified period of time in Genesis 2:4. So what does it mean in Genesis 1:5-2:2 when it's used in conjunction with ordinal numbers (i.e. the "first day," the "second day," the "third day," the "forth day," the "fifth day," the "sixth day," and the "seventh day")? Are these 24-hour periods or something else? Could "yom" as it is used here mean an unspecified period of time? How can we tell?We can determine how "yom" should be interpreted in Genesis 1:5-2:2 simply by examining the context in which we find the word and then comparing its context with how we see its usage elsewhere in Scripture. By doing this we let Scripture interpret itself. Ken Ham of Answers in Genesis wrote a good article on this. It's published at - http://www.answersingenesis.org/cec/study_guides/answersSG2.pdf. Mr. Ham writes, "The Hebrew word for day (yom) is used 2301 times in the Old Testament. Outside of Genesis 1, yom + ordinal number (used 410 times) always indicates an ordinary day, i.e. a 24-hour period. The words ‘evening’ and ‘morning’ together (38 times) always indicate an ordinary day. Yom + ‘evening’ or ‘morning’ (23 times each) always indicates an ordinary day. Yom + ‘night’ (52 times) always indicates an ordinary day."Now let’s look at the context in which we find the word "yom" used in Genesis 1:5-2:2...Day 1 - "And God called the light 'day' [yom] and the darkness he called 'night.' So the EVENING and the MORNING were the FIRST DAY [yom]" (Genesis 1:5).Day 2 - "So God called the firmament 'Heaven.' So the EVENING and the MORNING were the SECOND DAY [yom]" (Genesis 1:8).Day 3 - "So the EVENING and the MORNING were the THIRD DAY [yom]" (Genesis 1:13).Day 4 - "So the EVENING and the MORNING were the FOURTH DAY [yom]" (Genesis 1:19).Day 5 - "So the EVENING and the MORNING were the FIFTH DAY [yom]" (Genesis 1:23).Day 6 - "Then God saw everything that He had made, and indeed it was very good. So the EVENING and the MORNING were the SIXTH DAY [yom]" (Genesis 1:31).Day 7 - "Thus the heavens and the earth, and all the host of them, were finished. And on the SEVENTH DAY [yom] God ended His work which He had done, and He rested on the SEVENTH DAY [yom] from all His work which He had done" (Genesis 2:1-2).By describing each day as “the evening and the morning” it is quite clear that the Author of Genesis meant 24-hour periods. This was the standard interpretation up until the 1800s when a paradigm shift occurred within the scientific community, and the Earth's sedimentary strata layers were reinterpreted. Whereas previously the rock layers were interpreted as evidence of Noah's flood, the flood was thrown out by the scientific community and the rock layers were reinterpreted as evidence for an excessively old earth. Some well meaning but terribly mistaken Christians then sought to reconcile this new anti-Flood, ant-Bible interpretation with the Genesis account by reinterpreting "yom" to mean vast unspecified periods of time. This was a mistake.The truth is that the evidences in favor of Noah's flood and a young earth far outnumber those in favor of an old earth, and many of the old earth interpretations are known to rely upon faulty assumptions. Unfortunately, the scientific community is entrenched on the matter and apparently they refuse to change their minds despite the weight of evidence contrary to their currently accepted paradigm. But we must not let their stubborn refusal influence how we read the Bible. According to Exodus 20:9-11, God used six literal days to create the world in order to serve as a model for man's workweek: work six days, rest one. Certainly God could have created everything in an instant if He wanted to. But apparently He had us in mind even before He made us (on the sixth day) and wanted to provide an example for us to follow.Recommended Resource: Biblical Creationism by Henry Morris.