<P> The workweek and weekend are those complementary parts of the week devoted to labour and rest, respectively . The legal working week (British English), or workweek (American English), is the part of the seven - day week devoted to labour . In most of the Western world, it is Monday to Friday; the weekend is Saturday and Sunday . A weekday or workday is any day of the working week . Other institutions often follow the pattern, such as places of education . </P> <P> In some Christian traditions, Sunday is the "day of rest and worship". Jewish Shabbat or Biblical Sabbath lasts from sunset on Friday to the fall of full darkness on Saturday; as a result, the weekend in Israel is observed on Friday--Saturday . Some Muslim - majority countries historically had a Thursday--Friday or Friday--Saturday weekend; however, recently many such countries have shifted from Thursday--Friday to Friday--Saturday, or to Saturday--Sunday . </P> <P> The Christian Sabbath was just one day each week, but the preceding day (the Jewish Sabbath) came to be taken as a holiday as well in the twentieth century . This shift has been accompanied by a reduction in the total number of hours worked per week, following changes in employer expectations . The present - day concept of the' week - end' first arose in the industrial north of Britain in the early part of nineteenth century and was originally a voluntary arrangement between factory owners and workers allowing Saturday afternoon off from 2pm in agreement that staff would be available for work sober and refreshed on Monday morning . The Amalgamated Clothing Workers of America Union was the first to successfully demand a five - day work week in 1929 . </P> <P> Most countries have adopted a two - day weekend, however, the days of the weekend differ according to religious tradition, i.e. either Thursday--Friday, Friday--Saturday, or Saturday--Sunday, with the previous evening post-work often considered part of the weekend . Proposals have continued to be put forward for further reductions in the number of days or hours worked per week, on the basis of predicted social and economic benefits . </P>

Who came up with a 5 day work week