The Creator, in His infinite wisdom, gave us a year of approximately 365.25 days; a month of approximately 29.5 days, and a week of precisely seven days. These time periods, each an essential part of our calendar, bear no direct relationship to each other.

Years are not evenly divided into months. Nor are years an exact multiple of weeks. And months don't correspond to an exact number of weeks.

Years and months are regulated and defined by the orbits of the earth around the sun and the moon around the earth. These two orbits – natural cycles – are not well synchronized. In effect, they are disconnected.

The week, on the other hand, is completely independent of the orbits of the sun and moon. It has always been unalterably uniform. Eminent French astronomer Edouard Baillaud said the week "is without a doubt the most ancient scientific institution bequeathed to us by antiquity."

In the biblical record, the week was determined by the action of the Creator. He marked its length with the Sabbath, and in so doing, He established the rhythm of human life. The week does not require astronomical calculations or observation of equinoxes and new moons. The seven-day cycle is not natural. It is supernatural .

– Jim Wood