The Hajj (Arabic: حج‎ Ḥaǧǧ "pilgrimage", also spelled haj and hadj) is the pilgrimage to Mecca, Saudi Arabia. It is one of the largest pilgrimages in the world, and is the fifth pillar of Islam, a religious duty that must be carried out at least once in their lifetime by every able-bodied Muslim who can afford to do so.^[1] The Hajj is a demonstration of the solidarity of the Muslim people, and their submission to God (Allah in the Arabic language).^[2]

The pilgrimage occurs from the 8th to 12th day of Dhu al-Hijjah, the 12th and last month of the Islamic calendar. Because the Islamic calendar is a lunar calendar, eleven days shorter than the Gregorian calendar used in the Western world, the Gregorian date of the Hajj changes from year to year. Ihram is the name given to the special spiritual state in which Muslims live while on the pilgrimage.

Memorial Day is a United States federal holiday observed annually on the last Monday of May (May 28 in 2012).^[1] Formerly known as Decoration Day, it originated after the American Civil War to commemorate the fallen Union soldiers of the Civil War. (Southern ladies organizations and southern schoolchildren had decorated Confederate graves in Richmond and other cities during the Civil War, but each region had its own date. Most dates were in May.) By the 20th century Memorial Day had been extended to honor all Americans who have died in all wars. Memorial Day is a day of remembering the men and women who died while serving in the United States Armed Forces.^[2] As a marker it typically marks the start of the summer vacation season, while Labor Day marks its end.

By the early 20th century, Memorial Day was an occasion for more general expressions of memory, as people visited the graves of their deceased relatives, whether they had served in the military or not. It also became a long weekend increasingly devoted to shopping, family gatherings, fireworks, trips to the beach, and national media events such as the Indianapolis 500 auto race, held since 1911 on the Sunday of Memorial Day weekend.^[3]

A bank holiday is a public holiday in the United Kingdom or a colloquialism for public holiday in Ireland. There is no automatic right to time off on these days, although the majority of the population is granted time off work or extra pay for working on these days, depending on their contract.^[1] The first official bank holidays were the four days named in the Bank Holidays Act 1871, but today the term is colloquially (albeit incorrectly) used for public holidays which are not officially bank holidays, for example Good Friday and Christmas Day.

Prior to 1834, the Bank of England observed about thirty-three saints' days and religious festivals as holidays, but in 1834, this was reduced to just four: 1 May (May Day), 1 November (All Saints Day), Good Friday, and Christmas Day. In 1871, the first legislation relating to bank holidays was passed when Liberal politician and banker Sir John Lubbock introduced the Bank Holidays Act 1871, which specified the days in the table set out below.^[2] The English people were so thankful that they called the first Bank Holidays St Lubbock's Days for a while.^[3] Scotland was treated separately because of its separate traditions; for example, New Year is a more important holiday there.^{[citation needed]}

African Liberation Day on May 25 is an annual holiday in various countries in Africa, coinciding with African Union's Africa Day.

On April 15, 1958, in the city of Accra, Ghana, African leaders and political activists gathered at the first Conference of Independent African States. It was attended by representatives of the governments of Egypt (which attended as part of the United Arab Republic), Ethiopia, Ghana, Liberia, Libya, Morocco, Sudan, Tunisia, and representatives of the National Liberation Front of Algeria, and the Union of the Peoples of Cameroon. The conference was significant in that it represented the first pan-African Conference held on African soil.

According to the Church of Scientology, "Ethics may be defined as the actions an individual takes on himself to ensure his continued survival across the dynamics. It is a personal thing. When one is ethical, it is something he does himself by his own choice." ^[1]

According to founder L. Ron Hubbard's teachings, Scientology ethics is predicated on the idea that there are degrees of ethical conduct. ^[2]

Geek Pride Day is an initiative to promote geek culture, celebrated on 25 May. The date was chosen as to commemorate the release of the first Star Wars film, A New Hope on 25 May 1977 (see Star Wars Day), but shares the same day as two other similar fan "holidays": Towel Day, for fans of The Hitchhiker's Guide to the Galaxy trilogy by Douglas Adams, and the Glorious 25 May for fans of Terry Pratchett's Discworld.

The initiative originated in Spain in 2006 as "Orgullo Friki" and spread around the world via the internet.

Whit Monday or Pentecost Monday (also known as Monday of the Holy Spirit) is the holiday celebrated the day after Pentecost, a movable feast in the Christian calendar. It is movable because it is determined by the date of Easter.

Whit Monday gets its English name for following "Whitsun", the day that became one of the three baptismal seasons. The origin of the name "Whit Sunday" is generally attributed to the white garments formerly worn by those newly baptized on this feast.

May 27 (Western)

Prayer, Vigils, Fasting (pre-festival), Novenas, Retreats

Towel Day is celebrated every 25 May as a tribute by fans of the late author Douglas Adams.^[1] On this day, fans carry a towel with them to demonstrate their love for the books and the author, as referred to in Adams's The Hitchhiker's Guide to the Galaxy. The commemoration was first held in 2001, two weeks after Adams's death on 11 May 2001.^[2]

The original quotation that explained the importance of towels is found in Chapter 3 of Adams's work The Hitchhiker's Guide to the Galaxy.

Confederate Memorial Day, also known as Confederate Decoration Day (Tennessee) and Confederate Heroes Day (Texas), is an official holiday and/or observance day in parts of the U.S. South as a day to honor those who died fighting for the Confederate States of America during the American Civil War. Nine states officially observe Confederate Memorial Day: Alabama, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, and Texas.^[1]

Youth Day was celebrated throughout the former Yugoslavia on May 25. This was also a celebration of Josip Broz Tito's birthday. In the weeks preceding the date youth ran a relay around the country and on his birthday Tito was ceremonially presented with the baton. The baton, which had passed through all major cities, contained a symbolic birthday message, ostensibly from the youth of the whole country.

Youth Day was celebrated throughout the former Yugoslavia on May 25. This was also a celebration of Josip Broz Tito's birthday. In the weeks preceding the date youth ran a relay around the country and on his birthday Tito was ceremonially presented with the baton. The baton, which had passed through all major cities, contained a symbolic birthday message, ostensibly from the youth of the whole country.

May 27 (Western)

Prayer, Vigils, Fasting (pre-festival), Novenas, Retreats

Whit Monday or Pentecost Monday (also known as Monday of the Holy Spirit) is the holiday celebrated the day after Pentecost, a movable feast in the Christian calendar. It is movable because it is determined by the date of Easter.

Whit Monday gets its English name for following "Whitsun", the day that became one of the three baptismal seasons. The origin of the name "Whit Sunday" is generally attributed to the white garments formerly worn by those newly baptized on this feast.

Saints Cyril and Methodius (Greek: Κύριλλος καὶ Μεθόδιος, Old Church Slavonic: Кѷриллъ и Меѳодїи^[more]) were Byzantine Greek brothers born in Thessaloniki in the 9th century.^{[3][4][5][6][7][8][9][10]} They were Christian missionaries among the Slavic peoples of the First Bulgarian Empire, Great Moravia, and Pannonia. Through their work they influenced the cultural development of all Slavs, for which they received the title "Apostles to the Slavs". They are credited with devising the Glagolitic alphabet, the first alphabet used to transcribe Old Church Slavonic.^[11] After their deaths, their pupils continued their missionary work among other Slavs. Both brothers are venerated in the Orthodox Church as saints with the title of "equal-to-apostles". In 1880, Pope Leo XIII introduced their feast into the calendar of the Roman Catholic Church. In 1980, Pope John Paul II declared them co-patron saints of Europe, together with Benedict of Nursia.^[12]

The two brothers were born in Thessaloniki – Cyril in 827–828 and Methodius in 815–820. Cyril was reputedly the youngest of seven brothers; he was born Constantine,^[13] but took the name Cyril upon becoming a monk shortly before his death,^[14][15][16] according to the "Vita Cyrilli" ("The Life of Cyril"). Their father was Leo, a droungarios of the Byzantine theme of Thessaloniki, and their mother was Maria, who may have been a Slav.^[17]

Buddha's Birthday, the birthday of the Prince Siddhartha Gautama, is a holiday traditionally celebrated in Mahayana Buddhism.

In all east Asian countries, except Japan beginning in 1873, it is held on the 8th day of the 4th month in the Chinese lunar calendar, and the day is an official holiday in Hong Kong, Macau, and South Korea. The date varies from year to year in the Gregorian calendar: