Most theologians throughout church history agree that in using the phrase “the evening and the morning were the first day,” the creation account in Genesis is speaking of a literal 24- hour day, rather than a general time or a period of years.
“To understand the meaning of ‘day’ in Gen. 1, we need to determine how the Hebrew word for ‘day,’ yom, is used in the context of Scripture…A number, and the phrase ‘evening and morning,’ are used for each of the six days of creation (Gen. 1:5,8,13,19,23,31). Outside Gen. 1, yom is used with a number 359 times, and each time it means an ordinary day—why would Genesis 1 be the exception?
“Outside Gen. 1, yom is used with the word ‘evening’ or ‘morning’ 23 times. ‘Evening’ and ‘morning’ appear in association, but without yom, 38 times. All 61 times the text refers to an ordinary day—why would Genesis 1 be the exception?
“In Genesis 1:5, yom occurs in context with the word ‘night.’ Outside of Gen. 1, ‘night’ is used with yom 53 times—and each time it means an ordinary day. Why would Gen. 1 be the exception? Even the usage of the word ‘light’ with yom in this passage determines the meaning as ordinary day.
“There are words in biblical Hebrew (such as olam or qedem) that are very suitable for communicating long periods of time, or indefinite time, but none of these words are used in Gen. 1. Alternatively, the days or years could have been compared with grains of sand if long periods were meant. If we are prepared to let the words of the language speak to us in accord with the context and normal definitions, without being influenced by outside ideas, then the word for ‘day’ found in Gen. 1—which is qualified by a number, the phrase ‘evening and morning’ and for Day 1 the words ‘light and darkness’—obviously means an ordinary day (about 24 hours).” Ken Ham, et al., The New Answers Book
Hebrews 4:4 For He has spoken in a certain place of the seventh dayin this way: “And God rested on the seventh day from all His works”