Remember the Sabbath day, to keep it holy. Six days you shall labor, and do all your work, 10 but the seventh day is a Sabbath to the LORD your God. On it you shall not do any work, you, or your son, or your daughter, your male servant, or your female servant, or your livestock, or the sojourner who is within your gates. For in six days the LORD made heaven and earth, the sea, and all that is in them, and rested on the seventh day. Therefore the LORD blessed the Sabbath day and made it holy.I don't think this demands a literal 24 hr day reading of Genesis, and, in fact, I think we have good reason to see God's Sabbath extending far beyond a 24-hr period.
Someone is now saying, "Wait, are you saying God isn't working now, only resting." No. He is working...and he is resting. If God had stopped working even for a moment, the universe fall back into nonexistence - for he hold's it all together. The rest isn't absolute, but involves the establishment of stability. Significantly, God rests in his temple (i.e. Psalm 132:7-8, 13-14). God, having created a home for man and a temple for himself takes up his rest in his temple where he can govern and be worshiped.
Even more importantly, the work week ending in Sabbath is an earthly type of the heavenly reality. We are to work then rest just as God worked and rested. But, just as the earthly copy of God's home (the temple) of the heavenly home isn't meant to be taken overly literally, neither should we take the divine work week overly literally. None of would argue that heaven is only as big as Solomon's temple!
But the pattern is important. God worked then rested. The first man was to work faithfully, fulfilling the mandate of the covenant (Genesis 1:28). Adam failed and broke covenant (Hosea 6:7). Had Adam been faithful he would have been confirmed in righteousness and entered the Sabbath rest of God. Having failed, mankind is given, by God's grace, a new, faithful covenant representative - a Second Adam. He does the work, is faithful to the covenant, and brings God's people into God's Sabbath Rest (Heb. 4:8-11; actually, all of Heb 3&4 are important on this point). This rest, like God's rest, is eternal, but not to be equated with total inactivity (it's not napping). It's rest, the work having been done, and now the rewards can be enjoyed (as when Israel would be given rest in the Promised Land, free from harassment to enjoy the benefits; as when the people of God rest weekly to enjoy the benefits of being God's people - worship, God's presence, etc).
One last point. I had assumed one important point stood but didn't necessarily need to be articulated. But, just to be clear, I'm not saying God needed more time to get the job done! He could have accomplished the work of creation in seven literal days. He could have done it on his coffee break! But, I don't think the text demands a literal 24-hr day or a young earth, and I don't think we should erect this artificial barrier to belief.