Genesis 1 is structured in an interesting manner. It was structured by describing the acts of God and then it was evening, a day has past. The acts of God come before the day. Many a time, we count days because we are looking forward to some events - birthday, exams, release of result, an appointment, holiday. The Bible here counted the day to mark God's acts.

How we define our days should be by considering the acts of God and how we are instrument of His act instead of us counting our days to wait for certain events. Each day opens to the chance of God acting through and in us.