Long weekend
A long weekend is a weekend that is at least three days long (so, a three-day weekend), due to a holiday falling on either the Friday or Monday.
Most countries also feature many four-day weekends, in which two days adjoining the weekend are holidays. (Examples can include Easter Monday / Good Friday, and Christmas Day / Boxing Day.)
Further, in many nations, when a lone holiday occurs on a Tuesday or a Thursday, the gap between that day and the weekend may also be designated as a holiday, or set to be a movable or floating holiday, or indeed work/school may be avoided by consensus unofficially. This is typically referred to by a phrase involving "bridge" in most languages.
A special situation exists in France in some elementary schools, where there is no school on Wednesday: thus, any four-day weekend is essentially a "five-day weekend" for the kids and their teachers. Any four-day bridge, for example: Thursday (Holiday) and Friday (bridge day) for Ascension, is essentially a "five-day weekend" to some teachers.
Four-day bridge weekends are commonplace in non-English speaking countries, but there are only a couple of examples in English-speaking countries:
In the USA, the fourth Thursday of November is Thanksgiving; but the adjacent Friday is made in to a non-working day at some businesses. In Melbourne, Australia, the Melbourne Cup holiday is a Tuesday, but very many people modify their work arrangements to have the Monday off.
Linguistic idioms
In the United Kingdom and some other British Commonwealth countries, and in Ireland, the term is often known as a Bank Holiday weekend, since bank holidays always fall on Mondays.
The term for a four-day weekend in some Spanish-speaking countries is puente ("bridge") or simply "fin de semana largo".
In Spain, the bridge becomes a puente in some years when the anniversary of the Spanish Constitution of 1978 (December 6) and the Blessed Virgin Mary's Immaculate Conception (December 8) and a weekend plus a movable holiday form a block of five days.
In Chile, a "sandwich" is a day that falls between two holidays, independently of whether it's a holiday by itself or not. In the latter case, workers may take it off on account on vacation days, an action called "tomarse el sandwich" (lit.: "taking the sandwich"). In formal writings, the term "interferiado" is used instead of "sandwich". In colloquial contexts, these days, almost always a Monday or a Friday, may be called "San Lunes" or "San Viernes" (lit.: "Saint Monday" and "Saint Friday", respectively) as well.
France uses the same bridge idiom: faire le pont (literally meaning simply "to make the bridge") is the universal phrase used to mean taking additional holiday days, to make an "even longer" holiday. Remembering that in France there is no school (i.e. école élémentaire and collège) on Wednesdays, this can lead to very long "weekends" indeed. For example, if there is already an official holiday on Thursday, one could "faire le pont" on the Friday - leading to a five-day weekend (Wednesday through Sunday inclusive).
The same idiom applies in Italy, where they say 'Fare il ponte,' again literally, 'Make the bridge.' This could be a Thursday-Sunday weekend if the bridge was over Friday, or a Saturday-Tuesday weekend if the bridge was over a Monday.
The Portuguese do the same with ponte."
In Slovenian, the term podaljšan vikend ("prolonged weekend") is used for a three-day weekend. Four-day weekends also happen, because May 1 and May 2 are public holidays (both May Day). A peculiar coincidence are Christmas Day and Independence Day, falling on two consecutive dates.
In German, a bridge-related term is also used: a day taken off from work to fill the gap between a holiday Thursday (or Tuesday) and the weekend is called a Brückentag ("bridge day") in Germany and Switzerland, and a Fenstertag ("window day") in Austria. Since Ascension day is a holiday throughout Germany and Corpus Christi is a holiday in large parts of the country (both of these holidays are always on Thursdays), such "bridge days" are fairly common, though always unofficial in character. The "bridge day" terminology is also used in Israel ("yom gishur"/"יום גישור") and Flanders ("brugdag"; not so common in The Netherlands).
The term długi weekend (Polish for long weekend) is also commonly used in the Polish language. In Poland, such a phenomenon usually occurs several times a year. As well as the Easter weekend and the Christmas weekend, there is Corpus Christi weekend (Corpus Christi is always on Thursday and people usually take Friday off as well) and it may occur also around other holidays. However, the best known long weekend is at the beginning of May, when there are holidays of Labour Day on May 1 and 3 May Constitution Day. The weekend can in fact be up to 9 days long (April 28 – May 6) and, taking one to three days off work, Poles often go for small holidays then.
In Norwegian, the term "oval weekend" is used. An ordinary weekend is conceived of as "round" (although this is not stated explicitly), and adding extra days off makes it "oval". Norwegians also refer to "inneklemte" (squeezed in) days, which are between a public holiday and a weekend. This is typical for the Friday after Ascension Day, which always falls on a Thursday. It is common not to work on such days, so as to be able to extend the weekend to four days.
Also in Swedish, the days between a holiday and weekend are called "klämdagar" (squeezed-in days).
In Argentina and the USA, some national holidays that occur on a Tuesday, Wednesday, Thursday or Friday (sometimes even on a Saturday) are officially moved to the closest Monday in order to create a long weekend.
In Brazil, when a holiday occurs in a Tuesday or a Thursday, some sectors of the society, as government and education, turn the day between the holiday and the weekend into a holiday. The four-day or even the three-day weekends are called feriados prolongados ("Extended holidays") or its popular form feriadão ("big holiday"). The bridge day is usually called "imprensado" ("pressed (in between)") or "enforcado" ("hanged").
In Indonesia, when a holiday occurs on a Tuesday and Thursday, the day between that day and the weekend is colloquially termed "Harpitnas" ('Hari Kejepit Nasional') (lit. National Sandwiched Day, a play on Hardiknas, National Education Day) causing some institutions to declare a day off, or some students or employees unilaterally declaring a day off for themselves, thereby creating a long weekend.