On day four of the creation record in Genesis, God creates the sun, moon and stars. Some day-age Creationist believe that this is proof of an ancient, or old earth, since there is no way that we could have had a 24 hour day without these celestial bodies. Why not? Is God subject to the actions of the sun, moon and stars? or are they (sun, moon and stars) subject to God's will? Think of a ruler, a foot measurement (12 inches). Is a foot 12 inches because the ruler dictates that it is? or did man come along and say "This length of space is a foot and I'll make this ruler as a tool so that everyone is on the same page"? It's a tool. And in this way so is the sun moon and stars. As the NIV puts it "...and let them serve as signs to mark seasons and days and years". The sun, moon and stars mark days as the ruler would mark 12 inches.

In Genesis 1:3 God created Light and then in verse 5 He called the light Day and the darkness Night, and the evening and morning were the first day. So metaphorically, God created the 12 inches and on the fourth day created the ruler. Even without the sun, moon and stars we still had day and night and evening and morning. Nothing at all here indicates an age of time with the absense of sun, moon and stars, more likely a 24 hour day is indicated.