Week
The title of this article is ambiguous. For other meanings, see Week (disambiguation).
The week is a common unit of time of seven days in almost all cultures today. However, in most countries it is neither a legal unit nor a physical unit of measurement in the sense of unit systems. Nevertheless, according to the German Civil Code (e.g. § 188 Para. 2) and the Swiss Code of Obligations (Art. 77 Para. 1 No. 2 OR), deadlines can be specified in weeks, whereby in Germany the week is usually defined as Monday 0:00 hours to Sunday 24:00 hours (§ 21a Working Hours Act).
According to the recommendation established by the International Organization for Standardization (ISO) in 1975, the days of the week have had the following order since January 1976: Monday, Tuesday, Wednesday, Thursday, Friday, Saturday/Sunday and Sunday.
According to Jewish and Christian tradition, the week begins with Sunday. This is also the way it is done today in the USA, in Israel, in Arab countries as well as in Japan and China. The German term "Mittwoch" (Wednesday) also refers to the beginning of the week on Sunday and not on Monday. However, the calendars of most European countries note Monday as the first day of the week, as provided for in the ISO 8601 standard. According to ancient Persian tradition, the week begins on Saturday.
In Germany, the DIN standard DIN 1355 was valid from 1943, which was amended in 1975 with effect from 1976, then merged into EN 28601 in 1992 and replaced by the currently valid ISO 8601 in September 2006.
Weekday heptagram with the symbols of the weekdays: Sun (Sun, top), Moon (Mo, bottom right) and further along the green solid line to Mars (Tue), Mercury (Wed), Jupiter (Thu), Venus (Fri), Saturn (Sat)
Etymology
The word week is related to the words switch and change.
Permanent calendar including reading of the day of the week
