Scoffers of the Six-Day Creation have been known to say something akin to, "There were no days yet because the sun wasn't created until Day Four". Then they say that the Bible doesn't mean what it says (or just plain wrong), and commence to adding huge amounts of time in their conveniently rewritten or ignored biblical account so they can have an old universe and accommodate evolutionism.
|Image credit: Freeimages / Juan Ferran|
Yes, there is no reason that there could not be actual days without the sun. What is needed? Light, and Earth's rotation. Where did the light come from? The Bible doesn't say, but the best probable answer is the glory of God. Do a search online, use a Bible concordance, or maybe some Bible software like this one, and do a study on the word light. The words light and glory are frequently used together. Something else to consider: the sun is temporary, but God's glory is eternal. The universe began without the sun, and there will be on sun at the end of it all (Rev. 22:5). The sun being created on Day Four is not a problem. I recommend the following article for more:
In Genesis 1:3–5 we read: “And God said, ‘Let there be light.’ And there was light. And God saw the light that it was good. And God divided between the light and the darkness. And God called the light, Day. And He called the darkness, Night. And the evening and the morning were the first day.”It would be a bright idea to read the rest by clicking on "Light, life and the glory of God".
Genesis 1:14–19 tells us that the sun and the moon were not created until Day 4, nevertheless there was still a day-night cycle as at present (Exodus 20:11). To account for this, creationists usually conclude that God provided the Day 1 light source, that it was on one side of Earth, and that it was the cause of the day-night sequence on a rotating Earth.