Why Seven Days?

Enlarge Image Image Gallery WILLIAM A. BAKE/PITURESQUE

Article Tools

Image Gallery

Print

E-mail

Comments

RSS

SEASONS

COMING IN JUNE: The rings on Saturn will be the narrowest they've been in over a decade.

SKY CALENDAR OF SPECIAL EVENTS FOR
1994

FEBRUARY

MARCH

About the only astronomical time period to which the week roughly corresponds is the period occurring between the four major lunar phases; there are approximately seven days from new moon to first quarter moon, from the first quarter moon to full moon, and so on. But this hardly seems as if it would have been important enough-especially to agricultural civilizations of ancient times-to warrant making it a major unit in the calendar.

Interestingly enough, the length of the week has differed in various societies. Some West African societies have a week made up of just five days, while the Chinese once had 15-day weeks. But for now we will focus on the seven-day week that has been favored by Western civilization since the latter days of the Roman Empire and by international usage in modern times.

You might suppose that Jews and Christians came to adopt the seven-day week simply in imitation of God's six days of creation and one of rest, from the Book of Genesis. But there is another strand in the establishment of the seven-day week, and it goes back much further than the beginnings of the Hebrew culture and traditions. The very ancient Sumerian civilization of Mesopotamia apparently used the seven-day week as well. According to writer Guy Ottewell, the Sumerians—who numbered the days of their months-regarded the 7th, 14th, 21st, and 28th days as "ominous." Of course, to point this belief out still begs the question. Why did the Sumerians choose seven days as the number of the interval between each of their ominous days of the month?

The most likely answer is that there are seven celestial objects that have been known since ancient times to move regularly against the background of the distant unchanging stars: the five bright planets, the Sun, and the Moon. In the English language, the names of the days of the week are named partly for early Germanic and Norse gods: Tuesday for Tiw or Tiu (War God); Wednesday for Woden or Odin (King of Gods); Thursday for Thor (Thunder God); and Friday for Frigga (Queen of Gods). But Sunday and Monday are the days of the Sun and Moon, respectively, and Saturday is Saturn's Day.

What's more, in European cultures that speak languages derived from Latin, all of the days of the week are named for the Sun, Moon, and planets. And this brings us to a connection with our current month—Mardi Gras. The name, which means "Fat Tuesday," is the last day of feasting (and revelry) before the long fasting of Lent. The French name for Tuesday is Mardi, Mars's Day. What's the Latin term for the month of Mars? March, of course.

RSS | Comments | E-mail | Print