The legal workweek (a US term, in the UK called the working week) is part of the 7-day week devoted to labor, as opposed to rest. In many countries it is Monday to Friday. What constitutes the workweek is mandated either by law or custom. In Christian tradition, Sunday is Lord's Day and the day of rest and worship. The Jewish Sabbath, known as Shabbat, is from sunset Friday to when it is fully dark on Saturday. The French Revolutionary Calendar had ten day weeks and allowed decadi, one out of the ten days, as a leisure day.
The present-day concept of the weekend goes back to the Dies Solis (Day of the Sun) decreed by Constantine and the Sabbath. The weekend in Western countries comprises Saturday and Sunday, when most employees don't have to work. Whereas the sabbath itself was just one day each week, the preceding day also came to be taken off, because it was considered necessary to do preparatory tasks at home that would permit proper sabbath observance the next day, i.e., cessation from work.
Indonesia, the largest muslim country in the world, has a work week of Monday through Friday, with Saturday and Sunday as the weekend. Other Muslim-majority countries differ, with Friday a day of prayer, so the working week may adjust to allow people time to attend prayer. The legal work week in the Middle East is typically either Saturday through Wednesday (Saudi Arabia), Saturday through Thursday (as in Iran ) or Sunday through Thursday as in Egypt, Iraq, Jordan, and Syria. A working week of Sunday through Thursday, with Friday and Saturday as the weekend, is becoming more common, with Qatar shifting to this model in 2003, Bahrain and the United Arab Emirates in 2006, Kuwait in 2007, Oman in 2008, and Algeria in 2009
In 2009, formal proposals are also being discussed in Yemen and Saudia Arabia to shift to a Saturday to Thursday work week. This trend is to allow for respect of Fridays as the day for Jummah prayers in Muslim countries while also having more working days to overlap with international financial markets.
In Australia, the working week begins on Monday and ends on Friday. Although Australians generally work significantly long hours, the official working week varies between 35 and 40 hours per week (not including breaks).
The standard business office workweek in Bahrain begins on Sunday and ends on Thursday, with weekends being Friday and Saturday.
The standard business office workweek in Canada begins on Monday and ends on Friday, 40 hours per week.
In China, the working week begins on Monday and ends on Friday. China began the two-day weekend in 1995. Most workers work 5 days a week (including officials and most industries). Normally, the Chinese consider the week beginning with Monday and ending with Sunday. However, most shops as well as the museums and cinemas are open on Saturday and Sunday. Commercial establishments are generally open throughout the weekend.
In Europe, the standard full-time working week begins on Monday and ends on Friday. Most retail shops are open for business on Saturday. In the formerly communist states of EU and the Netherlands large shopping centres open on Sunday, however in the Netherlands this is highly controversial, as some political parties, especially the SGP, tend to disagree with it. In some European countries such as Germany and Denmark, there are laws regulating open hours for shops. Shops must, with exceptions, be closed in the evenings and on Sundays.
Denmark has a 37 hours working week.
The French people use different translations (fin de semaine, reposailles) but "weekend" is the most common using. President Sarkozy wants the shops to be open on sunday.
Before the extension of the five-day workweek it was known as semana inglesa ("English week").
In Sweden, the standard workweek is Monday through Friday, both for offices and industry workers. There is no law regulating the workweek, or shop opening hours, only trade union agreements with companies. Shops are almost always open on Saturdays and often on Sundays, especially food shops and shopping centres outside cities, so that employees there have to work.
The normal business working week is from Monday through Friday. However, many shops and services are open on Saturdays and increasingly so on Sundays as well. However the maximum opening times stores are allowed to open on a determined by the total floor space of a store. 
The EC Working Time Directive regulates that workers cannot be forced to work for more than 48 hours per week on average (although the UK allows individuals to opt out if they so choose). The minimum holiday entitlement is now 28 days per year but that includes Public Holidays. One could in theory work 6 hours every day for 337 days in a row. 
The standard working week in Hong Kong is Monday to Friday for most local and international companies. A handful still work Saturdays, but the old six day week largely was abandoned following governmental changes in 2006, under which various administrative and judicial bodies moved to a five day week. However, many civil services and banks remain open to consumers on Saturday mornings, and most shops and restaurants open early and shut late, seven days a week.
In India, the standard full-time working week begins on Monday and ends on Friday, making it a 5 day work week, 40 hours per week. The weekend is Saturday and Sunday.
The workweek is Monday through Friday, with weekends being Saturday and Sunday.
The standard business office workweek in Iran begins on Saturday and ends on Wednesday, with weekends being Thursday and Friday.
For most Israelis, the workweek begins on Sunday and ends on Thursday or Friday at noon to accommodate the Jewish Sabbath which begins Friday night. The standard workweek is 43 hours per week, while a workday is 8 hours per day.
The standard business office workweek in Japan begins on Monday and ends on Friday, 40 hours per week. This system became common between the years of 1980 and 2000. Before then, most workers in Japan worked full time from Monday to Friday, and half time on Saturday (called "Han don", means half-holiday. "don" from the Dutch word "Zondag"), 45-48 hours per week. On Friday many people say "HanaKin," which means "flowery Friday."
The standard business office workweek in Kuwait begins on Sunday and ends on Thursday, with weekends being Friday and Saturday.
The standard business office workweek in Oman begins on Saturday and ends on Wednesday, with weekend being Thursday and Friday.
In Pakistan the workweek runs from Monday to Saturday and generally a half day on Friday, making it a 6 day work week, 45/48 hours per week. The weekend is Sunday, But in some instances, some Companies implement a 40 Hours per week rule giving an off on Saturday as well, Making the weekend start from Friday night till Sunday.
In most instances, the workweek is Monday through Friday. 40 hours per week. But in some instances, some companies implement a 48 hours per week rule.
The workweek is Monday through Friday. Approximately 40 hours per week.
In Saudi Arabia, as with some other Gulf states in the Middle East, the workweek runs from Saturday to Wednesday and generally a half day on Thursday. Schools are closed on Thursday and Friday (Friday being the Muslim holy day). In contrast to many Eastern and Western nations, commercial establishments are generally open longest on weekends.
In Thailand, the workweek is Monday through Friday for approximately 40 hours per week (8 hours per day), as in European countries. However, most shops and some private companies also work and are open on Saturday and Sunday.
In secular Turkey, the workweek is Monday through Friday, as in European countries. However, most shops are open on Saturday and Sunday.
The normal business working week is from Sunday through Thursday. The maximum prescribed working hours for an adult employee is eight hours per day or forty-eight hours per week. However, the working hours may be increased to nine hours per day in the case of persons employed in trades, hotels, cafeterias, and as guards. Employees may not work for more than five consecutive hours per day without breaks for rest, meals and prayer. However, the resting and the meal breaks are not included in calculating working hours. In factories, where people work day and night shifts or jobs where, for technical and economical reasons, continued attendance is required, the UAE Ministry of Labour and Social Affairs specifies the manner in which employees may take intervals for rest, prayer and meals. Most malls are open 7 days a week.
The standard business office workweek in the United States is from Monday through Friday, 40 hours per week. However, many service providers are open for business on Saturday and Sunday as well.
Some colleges and universities afford students the opportunity to choose classes scheduled Monday/Wednesday and Tuesday/Thursday, giving the students an extra weekend day on Friday. Some college students take advantage of this trend and go out to bars and nightclubs on Thursday nights leading to the phrase "Thursday is the new Friday."