Week

The week is now in almost all cultures a common unit of time of seven days. However, it is neither a legal unit of measurement or a physical unit in terms of unit systems in most countries. Nevertheless, and the Swiss Code of Obligations (. Art. 77 paragraph 1 item 2 CO) can according to the German Civil Code ( eg, § 188, paragraph 2) times are given in weeks, in Germany the week sometimes as Monday 0: 00 clock is defined to Sunday 24:00 clock ( § 21a working Hours Act).

In Germany since 1943, the DIN standard DIN 1355 was valid, the 1975 amended with effect from 1976, then in 1992 went up in the EN 28601 and was replaced by the currently valid ISO 8601 in September 2006.

• 5.1 Numbering according to ISO 8601

• 7.1 Calculation in the U.S. and many other countries
• 7.2 Further calculation variants

Order of the days of the week

According to the 1975 by the International Organization for Standardization ( ISO) established the recommendation weekdays have since January 1976, the following order: Monday, Tuesday, Wednesday, Thursday, Friday, Saturday / Saturday and Sunday.

Start of week

According to Jewish, Christian and Islamic tradition, the week starts with Sunday. So it is now handled even in the United States and Arab countries. The German name " Wednesday" refers to a beginning of the week on Sunday and not Monday. However, the calendar of most European countries note the Monday as the first day of the week, as provided in ISO 8601. After old Persian tradition, the week starts with Sunday.

Etymology

The word week is related to the words and change course.

The seven-day week

Origins

The summary of seven days to a unit of one week can be explained by the length of a month ( moon ), which includes a little more than 28 days. The four phases of the moon ( new moon, waxing crescent, full moon, waning crescent ) then allow an obvious division of the 28 days of the month into four weeks of seven days each. An old naming and order of the days of the week comes from Babylonia and Egypt, where already in the Old Kingdom ( 3rd millennium BC) divided the month into the four moon phases and the associated religious sacrifices were offered. Each day was assigned to this deity.

In Semitic languages ​​the word for week based (Hebrew שבוע schawua, Arabic أسبوع ) on the same root as the name for the number seven in the appropriate languages ​​.

In the oldest written Torah and therefore Bible traditions (5th century BC) is explicitly a seven -day week called the first six days are designated by numbers, the seventh day, however, as a general " day of rest " is lifted, see Gen 2.2 EU. This has so far remains unclear whether the tradition of the Torah from the beginning was associated with the seven-day week, or whether two originally separate traditions were connected later. The term for the Sabbath " day of rest " is, however, attested until much later. The Namensherleitung is also not clear. Modern research discussed the one hand, the origin of the Hebrew term " SBT " ( " stop, cease from work to celebrate " ) and on the other hand, the Babylonian equivalent " šapattu " ( " Moon Festival "). In addition, assumptions are that the original archaic Babylonian " Moon Festival Month" with the respective holidays at 7./14./21./28. Day was retained by the Israelites, while the Babylonians adapting their calendar for months 29-30 days. In fact, the lunar cycle is about 29.5 days and results in a division of the year into twelve months. According to Christian tradition, most Christians celebrate the first day of the week, Sunday ( day of the sun, day, were on which the sun god sacrifices ), as a day of remembrance of the resurrection of Jesus of Nazareth. The commandment of Sabbath observance is reinterpreted in this sense ( " Remember the Sabbath day holy ").

In ancient times, in making the Egyptian- Babylonian zodiac the division to the Greeks and Romans. These names tradition learned early on the further transfer to India and Japan. ( See also Japanese days of the week. )

Official launch

When and by whom the still common counting days of the week has been set for the first time, can not be traced.

Today's seven-day week triggered under oriental influence the ancient Roman Nundinum from, possibly largely determined by the calendar reform of Gaius Julius Caesar. Legally, can be made ​​with the Emperor Constantine from 321 AD in the legislation on labor and judicial Tags freedom of Sunday, the liability of the 7 -day week, however, only.

There is no evidence that the sequence of the seven days of the week would have been since their introduction ever interrupted, not even by the reform of the calendar of the Gregorian calendar. Thus, it represents the most regular part of the Julian and the Gregorian calendar

The names of the seven days in Germanic culture

The Germans took over the seven- day week of the ancient cultures. In Germanic culture, the names are not as obvious as obtained in the Romance languages ​​, the home of classical, Latinized planets or gods name. The Germanic gods name but were adjusted in their meaning the Romance: For example, Frija ( for Friday) and Venus ( for venerdi, vendredi ) " content " related, as the thunder god Thor (regional and Donar, for Tuesday ) and Jupiter ( for jeudi, giovedi ).

The survey provides information on the names of the days of the week in different, even Germanic languages.

Saturday could also easily abbreviate with "SA".

If the weekday name is to be abbreviated, using the German mainly the two letter forms Mon, Tue, Wed, Thu, Fri, Sat, Sun Since a " Saturday" would hardly different from the "Sunday" abbreviated, instead, is here through the " Saturday, " addressed. In English, it is preferred rather the three-letter abbreviations mon, tue, wed, thu, fri, sat, sun. These aspects lead, for example in the localization of computer software to unexpected additional problems. In Japanese, the days of the week with the first respective characters are abbreviated (eg for日日 曜 日).

Calendar week

The year includes a minimum of 52 numbered calendar weeks (KW), although there are several variations in the week numbering. Depending on the applied rule is the first week of the year

• ISO ( DIN / ÖNORM / SN): the week that contains the first Thursday of the year ( ISO 8601, DIN 1355-1 earlier ); equivalently week, containing 4 January
• The week in which January 1st is a Monday, Tuesday, Wednesday or Thursday, or else the following week

Counting according to ISO 8601

The German -language calendar industry maintains strict accordance with the international standard ISO 8601, the Sunday designated as the last day of the week, instead of Saturday / Saturdays / Sabbath, as is customary in the Judeo -Christian- Islamic tradition.

Within the scope of the standards of the DIN German Institute for Standardization, the following rules are recommended since 1976 by ​​standardization:

• Every Monday and only Monday begins a new calendar week.
• The first calendar week is the one that contains at least four days of the new year.

From these points, the following properties are obtained:

• There are no incomplete calendar weeks, without exception, every KW contains exactly seven days.
• Every year has either 52 or 53 calendar weeks.
• One year exactly then has 53 calendar weeks, if it starts with a Thursday or closing: A normal year with 53 weeks begins and ends on a Thursday.
• A leap year 53 weeks starts either on a Wednesday and ends thus with Thursday or begins on a Thursday and ends on a Friday.

Representation in the form of a permanent calendar

Representation in a clear scheme

In March 1975 by the DIN German Institute for Standardization eV was recommended for the Federal Republic of Germany, the day of the week Monday, the ordinal number assigned to 1 (DIN 1355 ); it is the practice has developed to look at the Monday as the first day of the week and thus the beginning of the week. Previously there had been in the German standard work in January 1943, the regulation: " A week starts on Sunday at 0:00 and ends the following Saturday at 24:00 ". In the GDR, this change occurred in the year 1969/1970 in force. 1978, the UN decided that Monday was to internationally recognized as the first day of the week.

Examples:

• Calendar week KW 52, 2003: " 2003 - W52 " - Monday, December 22, 2003 to Sunday, December 28, 2003
• KW calendar week 1, 2004: "In 2004 -W01 " - Monday, December 29, 2003 to Sunday, January 4, 2004

Calculating in the U.S. and many other countries

In many parts of the world (eg, North America, Australia), the tradition of Judaism, Christianity and Islam has got to count Sunday as the first day of the week. In the U.S. and countries that also use the correct local schema, the following rules apply:

• Every Sunday begins a new calendar week
• On January 1 always starts - regardless of the day - the first calendar week

This can in turn derive some properties:

• The first and the last calendar week of the year do not have to be complete, ie they may contain less than seven days
• Every year, this is not a leap year or its December 31 is not a Sunday, has 53 calendar weeks
• If December 31 of a leap year is a Sunday, so is that Sunday is the only day in the 54th calendar week ( This occurs relatively rarely: Last in 2000, the next time in 2028 ).

A modified, in the U.S., however, neither standardized nor common form of this calculation scheme used, similar to DIN schema only full weeks and lays the first calendar week that fixed that contains the 1st of January. In this case then may already belong to the first calendar week of the following year, the day after the last Saturday in December, while a 54th calendar week never occurs.

In the U.S. business and in the local public communications calendar weeks are as above, however, rarely used in the form of continuous numbers. Instead, a week, usually referred to by its Monday, for example, " week of June, 20".

Further calculation variants

In Portuguese, the weekdays are counted except Saturday and Sunday, the Monday of the second and Friday is the sixth day. This means that the Saturday ( Sabbath ) is calculated as the seventh day of the week. It is also in Japan ( see Japanese era, weekdays ). In Islamic countries, Sunday is also counted as the first day of the week.

Other systems short periods of time

That the seven-day week system has today enforced in all major cultures in terms of population, such as the computation with ten digits. In earlier civilizations, but also other systems of the day count:

• In ancient Egypt, the calendar was divided into 36 weeks, included the ten days.
• In the Roman Empire there was an eight-day week, the Nundinae so-called because of the previous census included. In addition, in the three months Fixtage, Kalends, Nones and Ides were used. In the year 321 AD this system was replaced by the Christian week with Sunday as the official day of rest.
• With five-day and 13-day phase (s) calculated the Aztecs. The normal Aztec calendar was based on the solar year and was xihuitl ( among the Maya haab ). It comprised 18 months of 20 days plus five extra days that should have been ill full. Each month had four weeks to five days. The last day of the week was public market day ( tianquiztli ) and simultaneously fixed and rest day. Thus there were a total of 288 working days and 72 tianquiztli year. At the five unlucky days you should not work. This yielded a total of 365 days. But since the year is about six hours longer, the calendar and the actual solar year postponed. After far more prevalent opinion, this shift was not compensated for by switching days or in some other way.

• In many regions of West and Central Africa (eg, in the Kingdom of Kongo ) was based on a four-day week calendar. It was 1 week included 4 days of the month and the year 7 weeks counted 13 months plus 1 day. With the takeover of Christianity, the Christian calendar has increasingly reduced the use of this calendar.
• After the French Revolution Calendar 1792 introduced, there was a ten- day week. Per month, there were three such ten-day weeks, every month, therefore, had 30 days. At the end of five extra days were appended. To January 1, 1806 Napoleon abolished this new era again.
• The Soviet calendar of the October Revolution from 1929 to 1940 had a five-day week with six-week months.
• In Balinese Hinduism is used even today ritually several counting systems simultaneously ( Pakuwon ). The combination of these systems is 55 (= 1 2 3 4 5 6 7 8 9 10) result in different days. In practice, it is particularly important the combination of: