Check Out Every Single One Of The U.N.'s Special Days

If you thought your 2016 was looking busy, just be glad you're not the United Nations. The organization will be marking 129 "International Days" — not to mention assorted weeks, decades and a year.

Looking over the list is overwhelming but also enlightening. It's clear certain dates are more popular than others. The most extreme case is March 21, when five days share a spot on the calendar. That's especially odd when you realize that there are huge gaps without any days. January has only one: the International Day of Commemoration in Memory of the Victims of the Holocaust.

That's on the 27th, which is also the anniversary of the liberation of Auschwitz. It's common for dates to be chosen to connect with historical events. Others have been picked to line up with existing celebrations — that's why April 22 is International Mother Earth Day. And you'll notice a few don't have exact dates. One example: World Habitat Today, which falls on the first Monday in October.

None of the days would exist without the founding of the United Nations. That event spawned United Nations Day, which is held every October 24 and is one of the oldest on the list.

As for the newest? Two days are making a 2016 debut: International Day of Women and Girls in Science (February 11) and World Tsunami Awareness Day (November 5).

Here's the full list:

JANUARY

27 January

International Day of Commemoration in Memory of the Victims of the Holocaust

FEBRUARY

4 February

World Cancer Day

6 February

International Day of Zero Tolerance to Female Genital Mutilation

11 February

International Day of Women and Girls in Science

13 February

World Radio Day

20 February

World Day of Social Justice

21 February

International Mother Language Day

MARCH

1 March

Zero Discrimination Day

3 March

World Wildlife Day

8 March

International Women's Day

20 March

International Day of Happiness

21 March

International Day for the Elimination of Racial Discrimination

21 March

World Poetry Day

21 March

International Day of Nowruz

21 March

World Down Syndrome Day

21 March

International Day of Forests

22 March

World Water Day

23 March

World Meteorological Day

24 March

World Tuberculosis Day

24 March

International Day for the Right to the Truth concerning Gross Human Rights Violations and for the Dignity of Victims

25 March

International Day of Remembrance of the Victims of Slavery and the Transatlantic Slave Trade

25 March

International Day of Solidarity with Detained and Missing Staff Members

APRIL

2 April

World Autism Awareness Day

4 April

International Day for Mine Awareness and Assistance in Mine Action

6 April

International Day of Sport for Development and Peace

7 April

International Day of Reflection on the Genocide in Rwanda

7 April

World Health Day

12 April

International Day of Human Space Flight

22 April

International Mother Earth Day

23 April

World Book and Copyright Day

23 April

English Language Day

24 - 30 April

World Immunization Week

Note: Okay, technically it's a "week" but it's included on the calendar of "International Days"

25 April

World Malaria Day

26 April

World Intellectual Property Day

28 April

World Day for Safety and Health at Work

29 April

Day of Remembrance for all Victims of Chemical Warfare

30 April

International Jazz Day

MAY

3 May

World Press Freedom Day

8-9 May

Time of Remembrance and Reconciliation for Those Who Lost Their Lives During the Second World War

9-10 May

World Migratory Bird Day

15 May

International Day of Families

17 May

World Telecommunication and Information Society Day

21 May

World Day for Cultural Diversity for Dialogue and Development

22 May

International Day for Biological Diversity

23 May

International Day to End Obstetric Fistula

29 May

International Day of UN Peacekeepers

31 May

World No-Tobacco Day

JUNE

1 June

Global Day of Parents

1 June

"Vesak", the Day of the Full Moon

4 June

International Day of Innocent Children Victims of Aggression

5 June

World Environment Day

6 June

Russian Language Day at the UN

8 June

World Oceans Day

12 June

World Day Against Child Labour

13 June

International Albinism Awareness Day

14 June

World Blood Donor Day

15 June

World Elder Abuse Awareness Day

17 June

World Day to Combat Desertification and Drought

20 June

World Refugee Day

21 June

International Day of Yoga

23 June

United Nations Public Service Day

23 June

International Widows' Day

25 June

Day of the Seafarer

26 June

International Day against Drug Abuse and Illicit Trafficking

26 June

United Nations International Day in Support of Victims of Torture

JULY

4 July (first Saturday in July)

International Day of Cooperatives

11 July

World Population Day

15 July

World Youth Skills Day

18 July

Nelson Mandela International Day

28 July

World Hepatitis Day

30 July

International Day of Friendship

30 July

World Day against Trafficking in Persons

AUGUST

9 August

International Day of the World's Indigenous Peoples

12 August

International Youth Day

19 August

World Humanitarian Day

23 August

International Day for the Remembrance of the Slave Trade and Its Abolition

29 August

International Day against Nuclear Tests

30 August

International Day of the Victims of Enforced Disappearances

SEPTEMBER

5 September

International Day of Charity

8 September

International Literacy Day

12 September

United Nations Day for South-South Cooperation

15 September

International Day of Democracy

16 September

International Day for the Preservation of the Ozone Layer

21 September

International Day of Peace

25 September (date varies but always in last week of September)

World Maritime Day

26 September

International Day for the Total Elimination of Nuclear Weapons

27 September

World Tourism Day

OCTOBER

1 October

International Day of Older Persons

2 October

International Day of Non-Violence

5 October

World Teachers' Day

5 October (first Monday in October)

World Habitat Day

9 October

World Post Day

10 October

World Mental Health Day

11 October

International Day of the Girl Child

13 October

International Day for Disaster Reduction

15 October

International Day of Rural Women

16 October

World Food Day

17 October

International Day for the Eradication of Poverty

20 October

World Statistics Day

24 October

United Nations Day

24 October

World Development Information Day

27 October

World Day for Audiovisual Heritage

31 October

World Cities Day

NOVEMBER

2 November

International Day to End Impunity for Crimes against Journalists

5 November

World Tsunami Awareness Day

6 November

International Day for Preventing the Exploitation of the Environment in War and Armed Conflict

10 November

World Science Day for Peace and Development

14 November

World Diabetes Day

15 November (third Sunday in November)

World Day of Remembrance for Road Traffic Victims

16 November

International Day for Tolerance

19 November

World Toilet Day

19 November (third Thursday in November)

World Philosophy Day

20 November

Africa Industrialization Day

20 November

Universal Children's Day

21 November

World Television Day

25 November

International Day for the Elimination of Violence against Women

29 November

International Day of Solidarity with the Palestinian People

DECEMBER

1 December

World AIDS Day

2 December

International Day for the Abolition of Slavery

3 December

International Day of Persons with Disabilities

5 December

International Volunteer Day for Economic and Social Development

5 December

World Soil Day

7 December

International Civil Aviation Day

9 December

International Day of Commemoration and Dignity of the Victims of the Crime of Genocide and of the Prevention of this Crime

9 December

International Anti-Corruption Day

10 December

Human Rights Day

11 December

International Mountain Day

18 December

International Migrants Day

20 December

International Human Solidarity Day