Underdog Day is observed annually on the third Friday in December. America loves underdogs.  In sports, people tend to rally around the person or team that is not favored to win. Use #UnderdogDay to share your favourite underdogs, and discover who others consider to be underdogs in different fields!

Underdog Day

Romania’s National Day, or Great Union Day (Ziua Marii Uniri), is an annual public holiday on December 1 to celebrate the unification of Romanian provinces. Romania also has Constitution Day, Flag Day and Anthem Day.

National Day - Romania

An international day dedicated to raising awareness of the AIDS pandemic caused by the spread of HIV infection. It's an opportunity for people worldwide to unite in the fight against HIV, to show support for people living with HIV, and to commemorate those who have died of the disease.

World AIDS Day

National Day (Arabic: اليوم الوطني‎; Al Yawm Al Watani") is celebrated on 2 December each year in the United Arab Emirates.[1] It marks the UAE's Union Day between the seven emirates which was followed by the joining of the seventh emirate, Ras Al Khaimah, in 1972.

National Day - United Arab Emirates

This is an opportunity to celebrate the many beautiful and varied forms of wild fauna and flora and to raise awareness of the multitude of benefits that conservation provides to people. At the same time, this day reminds us of the urgent need to step up the fight against wildlife crime.

World Wildlife Conservation Day

International Cheetah Day celebrates these incredible animals while raising awareness about their threat of extinction. It can accelerate faster than a Ferrari, going from 0-75 mph in just 3 seconds, and comes with a self-grown paint-job that would make the fanciest car blush with envy.

International Cheetah Day

His Majesty the Late King’s Birthday falls on 5 December. Citizens get a holiday to pay respects to and honour the Late King.

His Majesty the Late King’s Birthday - Thailand

Second Advent Sunday

World Soil Day (WSD) is held annually on 5 December as a means to focus attention on the importance of healthy soil and advocating for the sustainable management of soil resources. #WorldSoilDay and #StopSoilErosion are great hashtags to use to further your activism!

World Soil Day

Army Day in Ukraine is a special annual observance dedicated to the nation’s armed forces on December 6. 

Army Day

In Chatham Islands Territory, a public holiday celebrates the founding of the islands’ first European settlement back in 1791. It’s called Chatham Islands Anniversary Day and is observed on the Monday nearest to 30 November.

Chatham Islands Anniversary Day and Westland Anniversary Day - New Zealand

Finland's Independence Day is a national public holiday, and a flag day, held on 6 December to celebrate Finland's declaration of independence from Russia in 1917.

Independence Day - Finland

Observed on December 5/6 in Western Christian countries and December 19 in Eastern Christian countries, it is the feast day of Saint Nicholas. It is a Christian festival with regard to his reputation as a bringer of gifts, as well as through the attendance of Mass or other worship services.

St Nicholas Day

St. Nicholas Day is celebrated on December 6 in many European countries, as well as areas across the world that boast a strong European influence.

Saint Nicholas Day

International Civil Aviation Day is annually observed December 7 to raise awareness of the importance of international civil aviation and the role that the International Civil Aviation Organization (ICAO) plays in international air transport.

International Civil Aviation Day

While the origins of this #PretendToBeATimeTraveler Day are unknown, we are certain that the creators of this unofficial holiday wanted people to pretend to be time travelers. Act like a time traveler, choose your time period and decide whether you are traveling to the past or the future.

Pretend to Be a Time Traveler Day #PretendToBeATimeTravelerDay

The Solemnity of the Immaculate Conception celebrates the solemn celebration of belief in the Immaculate Conception of the Virgin Mary. It is universally celebrated on December 8, nine months before the feast of the Nativity of Mary, which is celebrated on September 8.

Feast of the Immaculate Conception

This day was named for the character made famous by Emmett Kelly, who was born on this day in 1898. Weary Willie Day celebrates the clowning art and the impact that it has had on our lives. Share your favourite memories and clowning art with #WearyWillieDay on social media!

Weary Willie Day

International Anti-Corruption Day has been observed annually, on 9 December, since the passage of the United Nations Convention Against Corruption on 31 October 2003 to raise public awareness for anti-corruption. Take action and lead the change in holding leaders accountable for corruption!

International Anti-Corruption Day

Day of Saint Leocadia (Toledo)

December 10 is Constitution Day in Thailand, a day to remember the adoption of the country’s first permanent constitution in 1932. As the holiday is close to the late King’s Birthday on 5 December, some people take a few work days off to create a long break and be part of the activities.

Constitution Day - Thailand

Human Rights Day is celebrated annually across the world on 10 December every year. The date was chosen to honour the United Nations General Assembly's adoption and proclamation, on 10 December 1948, of the Universal Declaration of Human Rights (UDHR), the first global enunciation of human rights.

Human Rights Day #HumanRightsDay

Birthday of the Sultan of Selangor (Selangor)

The year 2002 was the International Year of Mountains. As this year drew to a close, the United Nations (UN) General Assembly proclaimed December 11 to be International Mountain Day. It aims to raise awareness  on the importance of Mountains for our lives, the ecosystem and the environment.

International Mountain Day

Jamhuri Day is a national holiday in Kenya, celebrated on 12 December each year. Jamhuri is the Swahili word for "republic" and the holiday is meant to officially mark the date when Kenya became an independent republic which happened on 12 December 1964.

Jamhuri Day - Kenya

Third Advent Sunday

Neutrality Day of Turkmenistan is the second most important state holiday in Turkmenistan. This day is celebrated in Turkmenistan annually on December 12.

International Day of Neutrality

Celebrated first in 2012, Official Lost and Found Day is an unofficial holiday that reminds people to not give up on the things they have lost and to increase their efforts to find them. Share any such experiences you have with #LostandFoundDay !

Lost & Found Day

Monkey Day is an unofficial international holiday on December 14, celebrating all things simian. The holiday was created and popularized by artists Casey Sorrow and Eric Millikin when they were art students at Michigan State University.

Monkey Day

Cat Herders Day is observed annually on December 15. This day is for those of us whose life or job is like herding cats.  This day celebrates those who can manage others and themselves no matter what chaos is thrown their way.

Cat Herders Day #CatHerdersDay

The National Archives and Records Administration joins in the national celebration of the Bill of Rights, the first 10 amendments to the Constitution, which spell out our rights as Americans

Bill of Rights Day (USA)

The Day of Reconciliation is a public holiday in South Africa held annually on 16 December. The holiday came into effect in 1995 after the end of apartheid, with the intention of fostering reconciliation and national unity for the country.

Day Of Reconciliation

Kazakhstan Independence Day is the main national holiday in the Republic of Kazakhstan, celebrated annually the 16th of December.

Independence Day - Kazakhstan

Wright Brothers Day is a United States national observation. It is codified in the US Code, and commemorates the first successful flights in a heavier-than-air, mechanically propelled airplane, that were made by Orville and Wilbur Wright on December 17, 1903, near Kitty Hawk, North Carolina.

Wright Brothers Day

Bake Cookies Day occurs in the middle of the holiday season, and is a great excuse to bake some delicious cookies to help you get through the cold, winter days. Share your sugary delights on social media with #BakeCookiesDay and share your best creations with friends and family!

Bake Cookies Day

Qatar National Day is a national commemoration of Qatar's unification in 1878. It is celebrated annually on 18 December. The holiday was established by a 21 June 2007 decree of the then Crown Prince and Heir Apparent Sheikh Tamim bin Hamad Al Thani.

National Day - Qatar

It is celebrated as a Christian festival with particular regard to his reputation as a bringer of gifts, as well as through the attendance of Mass or other worship services.

St. Nicholas Day

Fourth Advent Sunday

December 21 commemorates the birth of a challenging word game enjoyed by millions around the world.  To celebrate #CrosswordPuzzleDay , complete some crossword puzzles with your friends and family, or even have a friendly competition with each other to see who is quicker!

Crossword Puzzle Day #CrosswordPuzzleDay

Winter officially begins with the Winter Solstice on Saturday, December 21, 2021. This is the astronomical first day of winter in the Northern Hemisphere.

First Day of Winter

Each year on the Thursday before Christmas people across the United States participate in National Re-gifting Day.  This day was chosen in honor of office parties and the unique Christmas gift exchange that they do.

Re-gifting Day

National Farmer’s Day, known as Kisan Divas in Hindi, is celebrated every year on 23 December,  on the birthday of the 5th Prime Minister of India, Choudhary Charan Singh, also a farmer's leader, who introduced many policies to improve the lives of Indian farmers.

National Farmer’s Day (INDIA)

Christmas Eve is the evening or entire day before Christmas Day, the festival commemorating the birth of Jesus. Christmas Day is observed around the world, and Christmas Eve is widely observed as a full or partial holiday in anticipation of Christmas Day

Christmas Eve

Hanukkah is a Jewish festival commemorating the rededication of the Second Temple in Jerusalem at the time of the Maccabean Revolt against the Seleucid Empire. It is also known as the Festival of Lights.

Hanukkah Begins #Hanukkah

This public holiday is always celebrated on 24 December. It marks the anniversary of independence from Britain and France in 1951.

Independence Day - Libya

Christmas Day is one of the biggest Christian celebrations and falls on December 25 in the Gregorian calendar.

Catholic Christmas Day

Christmas is an annual festival commemorating the birth of Jesus Christ, observed on December 25 as a religious and cultural celebration among billions of people around the world. A feast central to the Christian liturgical year, it is preceded by the season of Advent or the Nativity Fast.

Christmas Day

Christmas Day is a public holiday in Poland on December 25 each year.  

Christmas is an annual festival commemorating the birth of Jesus Christ, observed primarily on December 25 as a religious and cultural celebration among billions of people around the world.

Christmas

Boxing Day is a secular holiday celebrated the day after Christmas Day. It originated in the United Kingdom and is celebrated in a number of countries that previously formed part of the British Empire. On this day, shops often have dramatic price reductions, so keep your eyes out for the best deals!

Boxing Day (Most regions)

The Isra and Mi'raj are the two parts of a Night Journey that, according to Islam, the Islamic prophet Muhammad took during a single night around the year 621. Within Islam it signifies both a physical and spiritual journey.

Isra and Mi'raj (Many regions)

Boxing Day, also known as St Stephen’s Day or Holy Szczepan, is a public holiday in Poland on December 26 each year.  

Second Day of Christmas

It originated in the United Kingdom and is celebrated in a number of countries that previously formed part of the British Empire.

Boxing Day

Isra and Mi'raj (Isra Me'raj, Israa and Mi'raaj, Laylat Al-Isra wa Al-Miraj, Lailat al Miraj, Night Journey and Ascension to Heaven) marks the night that the Prophet Mohammad traveled from Mecca to Jerusalem, ascended to heaven and returned.

Lailatul Isra Wal Mi Raj

Proclamation Day in South Australia celebrates the establishment of government in South Australia as a British province. The province itself was officially created and proclaimed in 1834 when the British Parliament passed the South Australia Act.

Proclamation Day - Australia

A day to commemorate Saint Stephen, the first Christian martyr or protomartyr, celebrated on 26 December in the Latin Church and 27 December in Eastern Christianity.

St Stephen's Day - France

Feast of the Holy Family

December 27 is a bank holiday in the United Kingdom only in some years, depending on which day Christmas Day or Boxing Day occur. 

Bank Holiday

Across the United States, fruitcake lovers young and old, observe National Fruitcake Day each year on December 27. To celebrate, try your hand at baking some homemade fruitcake or gift your favorite fruitcake fro your local bakery to your family and friends!

Fruitcake Day

Christmas Day observed (Balearic Islands)

December 28 is a bank holiday in the United Kingdom only in some years, depending on which day Christmas Day or Boxing Day occur.

Tired of all the holiday activities? Need a break before the New Year fun begins? Get your family and friends together for a quiet and fun night in on Card Playing Day. Share your fun and inspire others to do the same by using #CardPlayingDay on social media!

Card Playing Day

Tick Tock Day, observed annually on December 29th, reminds us to complete any unfinished business that might need addressing before the end of the year. Make sure to use #TickTockDay to post on social media upon any achievements made!

Tick Tock Day

The Independence Day of Mongolia is the main state holiday in Mongolia. This date is celebrated annually on 29 December. It marks Mongolia's independence from China in 1921. Independence Day is also the term used for Constitution Day on November 26.

Independence Day / Revolution Day - Mongolia

Rizal Day is a Philippine national holiday commemorating the life and works of José Rizal, a national hero of the Philippines. It is celebrated every December 30, the anniversary of Rizal's 1896 execution at Bagumbayan (present-day Rizal Park) in Manila.

Rizal Day

New Year's Eve is the last day of the year in the Gregorian calendar. Many parties to welcome the New Year are held in in the United States on New Year's Eve.

New Year's Eve

In the Gregorian calendar, New Year's Eve, also known as Old Year's Day or Saint Sylvester's Day in many countries, the evening or the entire day of the last day of the year, is on 31 December. The last day of the year is commonly referred to as “New Year’s Eve”.