Unofficial observances

April Fools' Day or April Fool's Day is an annual custom in many Western countries on the 1st of April consisting of practical jokes, hoaxes, and pranks. Jokesters often expose their actions by shouting "April Fool[s]!" at the recipient. Mass media can be involved with these pranks, which may be revealed as such the following day. The custom of setting aside a day for playing harmless pranks upon one's neighbor has been relatively common in the world historically.

day for the appreciation of teachers

mathematical holiday on March 14

Black Friday is the Friday after Thanksgiving in the United States. It traditionally marks the start of the Christmas shopping season and is the busiest shopping day of the year in the United States. Many stores offer highly promoted sales at heavily discounted prices and often open early, sometimes as early as midnight or even on Thanksgiving. Some stores' sales continue to Monday or for a week.

unlucky day in popular superstition

holiday celebrating the works of Douglas Adams

annual international observance of student community

an observance of when copyrights expire and works enter into the public domain.

marketing term for the Monday after the Thanksgiving holiday in the United States, online equivalent to Black Friday

code-term that refers to the consumption of cannabis

celebration which takes place on 8 August, every year

day that is marked in Japan, South Korea, Taiwan, and China on March 14, one month after Valentine's Day

annual commemoration of Charles Darwin and science

unofficial holiday celebrating persons not in partner relationships; originally from China (November 11)

day of protest against cosumerism

Bloomsday (Irish: Lá Bloom) is a commemoration and celebration of the life of Irish writer James Joyce, observed annually in Dublin and elsewhere on 16 June. The day is named after Leopold Bloom, the protagonist of Joyce's 1922 novel Ulysses, the events of which take place on Thursday, 16 June 1904. Joyce chose to set his novel on this date as it was the date of his first sexual encounter with his wife-to-be, Nora Barnacle.

holiday

annual observance on May 4th to celebrate the Star Wars media franchise

world day

annual observance

parodic holiday created in 1995

world day

unofficial commemoration of the Avogadro constant

annual event

annual event in April to celebrate independently-owned record stores

abbreviated as SAAD, an unofficial celebration day for system administrators

pride celebration for autistics

International observance on 13 November.

world day to celebrate the International System of Units on the anniversary of the signing of the Metre Convention

action day

Festivus () is a secular holiday celebrated on December 23 as an alternative to the perceived pressures and commercialism of the Christmas season. Originally created by author Daniel O'Keefe, Festivus entered popular culture after it was made the focus of the 1997 Seinfeld episode "The Strike", which O'Keefe's son, Dan O'Keefe, co-wrote.

the day that the Sky Travel company considers to be the unluckiest day of the year; a marketing gimmick

thumb|right|Humpty Dumpty wearing the cravat he received as an unbirthday present from the White King and Queen. From Through the Looking-Glass, illustration by [[John Tenniel.]] An unbirthday (originally written un-birthday) is an event celebrated on all days of the year which are not a person's birthday. It is a neologism which first appeared in Lewis Carroll's 1871 novel Through the Looking-Glass. The concept gave rise to "The Unbirthday Song" in the 1951 animated feature film Alice in Wonderland.

yearly event to promote Open Standards

song by Earth, Wind & Fire

informal holiday oriented toward single people in South Korea

unofficial holiday

Annual event

observance

awareness day

awareness day for people to gather and watch the skies for unidentified flying objects

unofficial observance

unofficial observance

International LGBT supporting day

international day supporting the fetish and BDSM community

thumb|A Hanukkah bush that some Jewish families display in their homes for the duration of Hanukkah and Christmas. Unlike a Christmas tree it would be without any Christianity-themed ornaments and use the colour blue. Chrismukkah is a pop-culture portmanteau neologism referring to the merging of the holidays of Christianity's Christmas and Judaism's Hanukkah. It first arose in the German-speaking countries within middle-class Jews of the 19th century. After World War II, Chrismukkah became particularly popular in the United States, but is also celebrated in other countries.

Day of celebration for children and children related causes in India

annual celebration of body acceptance

Satirical holiday celebrated on 14 April

annual promotional event organized by the IASC

Annual event

Observance day on January 30

annual event

festival celebrated around Saint John's day's eve in Spain

celebration day in Bilboa

unofficial international holiday

commemorative day

annual LGBTQ awareness day

Unofficial observance, September 22

Holiday in the United States