Week

For more details on each day of the week, see days of the week.
For the TV station in the Peoria-Bloomington, Illinois market, see WEEK-TV.

A week (symbol wk, also called sennight or sevennight) is a unit of time longer than a day and shorter than a month. In most modern societies the week is a period of seven days. The weekly cycle of seven days runs independently of the cycle of a calendar. The common denominator in both cases is the day.

There are various explanations of why the number seven was chosen. There are seven natural celestial objects which are visible to the naked eye and which move around the sky independent of the celestial dome: i.e., the Sun, the Moon, Mercury, Venus, Mars, Jupiter and Saturn. The number seven also divides more or less evenly into the length of both the lunar month and the year: the lunar month is approximately four seven-day weeks long (28 days versus 29.53 days) and the year is approximately 52 seven-day weeks long (364 days versus 365.24 days.) Seven is also the largest prime number which is less than the number ten, which is the base for most counting systems.

Contents

Origins

Astronomy

All early cultures were exposed to the night sky. The seven celestial objects visible with the naked eye (that moved in a way that clearly indicated they were not stars) worked their way into the myths and legends of most early cultures. Time was and still is easily measured by celestial events, the spring equinox for example, occurs approximately every 365 days. It was easy to adapt the other 7 objects clearly seen floating about in the sky to measure the passage of time. The Sun, Moon and five visible planets gave their names to the weekly cycle of days.

Celestial Object Sumerian Babylonian Greek Latin English Day name
Moon Nanna Sin Selenê Luna Moon Monday
Mars Gugalanna Nergal Ares Mars Mars Tuesday
Mercury Enki Nabû Hermes Mercurius Mercury Wednesday
Jupiter Enlil Marduk Zeus Iuppiter Jupiter Thursday
Venus Inanna Ishtar Aphroditê Venus Venus Friday
Saturn Ninurta Ninurta Kronos Saturnus Saturn Saturday
Sun Utu Shamash Helios Sôl Sun Sunday

This pattern lent itself to early religious teachings (Greek mythology for example) for most all knowledge -- astronomy, reading and writing, and most forms of education -- came from religious centers. Two in particular -- astronomy and religion -- often went hand in hand.

Jewish and Christian concepts of the seventh day sabbath

The concept of the Jewish and Christian seven-day week (Hebrew "shavua") is reflected in the Book of Genesis (the first book of the Torah and the Old Testament.) God creates the universe, earth, animals, and man in six days, resting on the seventh day, which is the Sabbath.

The existence of the sabbath day within the context of the seven-day week was affirmed. After the Exodus, manna appeared on all mornings except for the sabbath morning. Manna collected on other mornings rotted if held overnight but manna which was collected on the eve of the sabbath remained fresh for two days [1]. Observance of the sabbath is included in the Ten Commandments.

In Judaism, with emphasis on the Shabbat and the significant number seven, the week did not retain a lunar connection; by the time of the second temple it was defined only as a period of seven days, independent of the new moon. The new moon, heralding a new calendar month and observed as Rosh Chodesh, and the days of the month, are calculated according to the rules of the lunisolar Hebrew calendar.

From Judaism the week passed over to Christianity.[2]. Jesus did miraculous healings on the sabbath [3] and declared himself to be Lord of the sabbath [4].

Other religions have also set apart a day for particular religious activities within the context of a seven-day week.

European and Near Eastern week

The week's existence in ancient cultures may be traced to the number of celestial objects visible to the naked eye, such as exists with the day, the month, and the year. The week as a subdivision of the month may have independently arisen in Babylonia (or Sumer) and spread westward through Aramaea and Canaan, where each lunar month was divided into four parts, corresponding to the four phases of the moon. The first week of each month began with the new moon, so one or two days of the lunar month were not reckoned at all (or else some weeks were eight days). Every seventh day ("sabbatum") was regarded as an unlucky day.

Weekday heptagram used for the planets or the days of the week

It has been suggested that a seven-day week might be much older. The seven-day planetary week originated in Hellenistic Egypt.

The Roman Republic and Empire, like the Etruscans, also used a "market week" of eight days (known as the nundinal cycle). From around the 1st century, with the spread of Christianity, the Roman eight-day week was replaced gradually by the seven-day week.

The seven-day weekly cycle is known to have remained unbroken in Europe for almost two millennia despite changes to the Alexandrian, Julian, and Gregorian calendars. The date of Easter Sunday can be traced back through numerous computistic tables to an Ethiopic copy of an early Alexandrian table beginning with the Easter of 311 as described by Otto Neugebauer in Ethiopic astronomy and computus. Only one Roman date with an associated day of the week exists from the 1st century and it agrees with the modern sequence, if properly interpreted. Jewish dates with a day of the week do not survive from this early period. The Jewish week had been in use for at least 1,000 years before its adoption by the Roman Empire.

Hindu week

The seven-day week became established in both the West and East according to different paths. Hindu civilization used a seven-day week. It is mentioned in the Ramayana, a sacred epic written in Sanskrit about 500 BCE, and translated as follows:

Hindu English
Bhanu-vaar Sunday
Soma-vaar Monday
Mangal-Vaar   Tuesday
Bud-Vaar Wednesday
Guru-Vaar Thursday
Shukr-Vaar Friday
Shani-Vaar Saturday

The meaning of the name of the days of the week in Sanskrit, above, is equivalent to English names: e.g., "Shani-Vaar," where Shani = Saturn and Vaar = Day.

Chinese week

The earliest known reference in Chinese writings is attributed to Fan Ning, who lived in the late 4th century, while diffusions via India are documented with the writings of the Chinese Buddhist monk Yi Jing and the Ceylonese or Central Asian Buddhist monk Bu Kong of the 7th century. The Chinese transliteration of the planetary system was soon brought to Japan by the Japanese monk Kobo Daishi; surviving diaries of the Japanese statesman Fujiwara Michinaga show the seven day system in use in Heian Period Japan as early as 1007. In Japan, the seven day system was kept in use (for astrological purposes) until its promotion to a full-fledged (Western-style) calendrical basis during the Meiji era.

The Chinese use of the seven day week (and thus Korean, Japanese, Tibetan, and Vietnamese use) traces back to the 600s CE. The 28 stars were arranged in order of sun, moon, fire, water, wood, gold, earth, and every 7 days were called "qi-yao". The days were assigned to each of the luminaries, but the week did not affect social life or the official calendar. The law in the Han Dynasty required officials of the empire to rest every 5 days, called "mu", while it was changed into 10 days in the Tang Dynasty, called "huan" or xún (旬). With months being almost 3 weeks long (alternating 29 and 30 days) the weeks were labelled shàng xún (上旬), zhōng xún (中旬), and xià xún (下旬) which mean roughly "upper", "middle" and "lower" week. The 7 days "week" in ancient China is mostly kept in astrological purposes and cited in several Buddhist texts until the Jesuits reintroduced the concept in the 16th century. Thus the 19th century Japanese, when adopting the seven day western week, took their own astrological week with names for the days of the week that corresponded to the English names (and in fact were better preservations of the original Babylonian concepts, the English day names having been conflated with gods from Germanic mythology).

Market-day week

Although seven day weeks are common to all modern societies now, anthropologists note that weeks of other durations (varying from three to eight days) are found in many pre-modern societies. They also observe that the name for "week" is often the same as that for "market day", suggesting the concept of a week is likely to arise in any agrarian or pre-agrarian society where people have marketplaces or market days. In sparsely populated areas where trade is not conducted every day it is essential that farmers and consumers agree in advance on what day they will meet, especially if the walk to market takes several hours or days. The week (meaning a fixed count of days) was much simpler and more precise way of doing this when compared with a lunar calendar-based system or a system based on the seasonal rotation of the celestial sphere. Being based on a count kept by people rather than on the relative motion of the moon and stars, the week was not "heavenly", but in the traditional seven-day week, this was overcome by assigning the sun, moon, and the five planets known to the ancients (Jupiter, Mercury, Mars, Venus, Saturn) each to a specific day of the week.

Weeks and the calendar year

The weekly cycle runs concurrently with regular calendar cycles. The weekly cycle is not based on any astronomical phenomena. Besides being of religious significance, it also is convenient in commercial and social contexts.

Some novel calendars have been designed which synchronise the weeks and years by adding a leap week or weekless days to the calendar. The advantage of these calendar systems is that each year a given date always falls on the same day of the week. For example, the proposed World Calendar has 52 weeks and one or two extra weekless days each year, which do not count in the weekly cycles.

A week of ten days was tried in the short-lived 18th century French Revolutionary Calendar which had 36 weeks of 10 days and five or six extra weekless days. The former Icelandic calendar had years of 52 or 53 weeks. Instead of adding extra weekless days, the number of weeks in the calendar year varied. An early Norse calendar, from the beginning of the Viking Age, had five day weeks, called fimmts, arranged in 12 months of six fimmts each, with five ceremonial days not part of any month. The Hermetic Lunar Week Calendar uses the lunar week which is a quarter of a lunation and has 6, 7, 8, or 9 days (average 7.382647 days).

First day of the week

In Jewish, Western Christian and Greek Orthodox tradition, the first day of the week is Sunday. The Hebrew, Ecclesiastical Latin and Medieval and Modern Greek languages number most of the days of the week. In Hebrew, Sunday through Friday are numbered one through six; in Ecclesiastical Latin, Monday through Friday are numbered the second through the sixth days of the week (feria); in Medieval and Modern Greek, Monday through Thursday are numbered the second through fifth. For many Western Christians and Jews, Sunday remains the first day of the week. Most, though not all, business and social calendars in North America mark Sunday as the first day of the week.

In most of Europe, and some other countries, Monday is considered to be the first day of the week. Monday is literally named as such in Baltic languages, for example Lithuanian (pirmadienis - means First Day); in Estonian (esmaspäev - means First Day); Hungarian (hétfő - means literally Head of The Seven/Week); Basque (astelehen - means Week-First) and Mandarin (pinyin Xīngqí Yī, literally means Weekday One). In Slavic languages, Tuesday, Thursday and Friday were named literally for their number after Monday[5], a meaning still conserved in Russian (for example Tuesday: вторник - vtórnik - means second).

The ISO prescribes Monday as the first day of the week with ISO 8601 for software date formats.

Work week and weekends

Main article: Workweek

The seven-day workweek is generally composed of five working days ("weekdays") and two non-working days (the "weekend"), though which days of the week are which varies from country to country. In countries like Japan, a sixth workday, such as a half-day on Saturday, has been observed by some. Even among countries that share the same weekend days, the determination of the first day of the week may vary.

Facts and figures

In a Gregorian mean year there are exactly 365.2425 days, and thus exactly 52.1775 weeks (unlike the Julian year of 365.25 days or 525⁄28 weeks, which cannot be represented by a finite decimal expansion). There are exactly 20871 weeks in 400 Gregorian years, so 10 April 1605 was a Sunday just like 10 April 2005.

A system of Dominical letters has been used to determine the day of week in the Gregorian or the Julian calendar.

Week number

Weeks in a Gregorian calendar year can be numbered for each year. This style of numbering is commonly used (for example, by businesses) in some European and Asian countries, but rare elsewhere.

ISO 8601 includes the ISO week date system, a numbering system for weeks – each week begins on a Monday and is associated with the year that contains that week's Thursday (so that if a year starts in a long weekend Friday–Sunday, week number one of the year will start after that). For example, week 1 of 2004 (2004W01) ran from Monday 29 December 2003 to Sunday, 4 January 2004, because its Thursday was 1 January 2004, whereas week 1 of 2005 (2005W01) ran from Monday 3 January 2005 to Sunday 9 January 2005, because its Thursday was 6 January 2005 and so the first Thursday of 2005. The highest week number in a year may be 52 or 53 (it was 53 for year 2004).

The numbering system in different countries may deviate from the international ISO standard. There are at least six possibilities[6] [7]:

First day of week First week of year contains Weeks assigned twice Used by/in
Monday 1 January, 1st Sunday, 1–7 days of year yes UK
Monday 4 January, 1st Thursday, 4–7 days of year no Most of Europe ISO 8601(1988), European Norm EN 28601 (1992)
Monday 7 January, 1st Monday, 7 days of year no
Wednesday 1 January, 1st Tuesday, 1–7 days of year yes
Saturday 1 January, 1st Friday, 1–7 days of year yes
Monday 1 January, 1st Saturday, 1–7 days of year yes USA

Roman Catholic liturgical week

Prior to Christianity, the week had already been regarded as a sacred institution among the Jews owing to the law of the Shabbat and its association with the first chapter of Genesis. The mixed practices of early Christian groups, which began with Jewish majorities, have been subject to varying interpretations. Many continued Sabbath meetings in synagogues (Acts passim); many celebrated "the first day of the week" (Acts 20:7; 1 Cor. 16:2; cf. Rev. 1:10), also called the "eighth day"; but the seven-day weekly cycle remained undisturbed. Depending on location and timing within the first and second centuries, uniquely Christian meetings may have formed either an annual or a weekly cycle, or both.

The eighth day, according to the Epistle of Barnabas (xv), was "the beginning of another world .... wherefore also we keep the eighth day for rejoicing, in the which also Jesus rose from the dead and having been manifested ascended into the heavens." The Didache directs (viii), "Let not your fasts be with the hypocrites; for they fast on the second and fifth days of the week, but do ye fast on the fourth and on the day of preparation" (the sixth day, prior to the original Sabbath); and (xiv), "And on the Day of the Lord come together and break bread and give thanks." By the time of Tertullian, the first day in each week was regarded as commemorating the resurrection; it has also been suggested that the fourth and sixth days reflect the betrayal and passion of Christ. Over the first four centuries CE, Sunday gradually replaced the original Sabbath as the primary day of religious observances, and, eventually, as the primary day of rest.

In Roman Catholic liturgy, this simple week gave place in time, as feasts were introduced and multiplied, to an annual calendar, but the week, newly dominated by the special status of Sunday, retained its importance; this can be inferred from Amalarius, who preserves the particulars of the arrangement accepted in the Aachen chapel royal in 802, by which the whole Psalter was recited in the course of each week. In its broader features this division was identical with that theoretically imposed by the Roman Breviary until the publication of the Apostolic Constitution "Divine afflatu", November 1, 1911; and the Carlovingian arrangement was apparently substantially the same as that already accepted by the Roman Church. In the sixth century, St. Benedict had also said that the entire Psalter was to be recited at least once in the week, and a similar arrangement was attributed to Pope St. Damasus.

The Catholic church also devoted particular days to particular subjects: the Office of the Blessed Virgin on Saturday, Masses of the Passion on Friday during Lent, and Pope Leo XIII's arrangement of Votive Offices for special week days. In the early Middle Ages, Thursday may have been regarded in the West as a sort of lesser feast or Sunday, probably because it was the day assigned to the Ascension (cf. Bede, Historia ecclesiastica gentis Anglorum, IV, 25). The Breviary approved after the Council of Trent assigned certain devotions, such as the Office for the Dead and Gradual Psalms, to weekly recitations, particularly on the Mondays of Advent and Lent.

See also

References

  1. ↑ Exodus 16:4-5,Exodus 16:15,Exodus 16:19-26
  2. ↑ Cohen, Simon, director of research (1943). "Week". Universal Jewish Encyclopedia. 10. Landman, Isaac, ed.. p. 482. 
  3. ↑ Matthew 12:9-13, John 5:1-9
  4. ↑ Matthew 12:8
  5. ↑ The Journal of the Royal Astronomical Society of Canada, June 1999 Volume 93 Number 3 (677) (pdf)
  6. ↑ Weeknumber sorted by definition
  7. ↑ Calendar Weeks

Further Reading

External links