Throughout the year there are so many awareness days, commemorative days, special days, celebrations, holidays, observances, etc, etc. These can be great as blog post inspiration, or just for getting a bit of extra traffic to an existing post by promoting it as a tie-in.
Read on for a list of notable dates for April - if the day has its own website or wiki page, I've linked to it. A lot of the weirder ones are USA based unofficial 'national days'; I've included them in the list if they've crossed the pond, or had a fair number of media hits when I googled them.
*Note: I've not included any dates related to Easter.
1st
☆ April Fools' Day.
☆ Arbor Day - Tanzania.
☆ Atheist Day.
☆ Civil Service Day - Thailand.
☆ Cyprus National Day.
☆ Edible Book Day.
☆ Fossil Fools Day.
☆ Kha b-Nisan - Assyria.
☆ One Cent Day - USA.
☆ Sourdough Bread Day.
2nd
☆ Ferret Day.
☆ International Children's Book Day.
☆ Malvinas Day - Argentina.
☆ National Peanut Butter and Jelly Day - USA.
☆ Odisha Day - Odisha, India.
☆ Thai Heritage Conservation Day - Thailand.
☆ Unity of Peoples of Russia and Belarus Day - Belarus.
☆ World Autism Awareness Day.
3rd
☆ Chocolate Mousse Day.
☆ Find a Rainbow Day.
☆ Fish Fingers and Custard Day.
☆ Tweed Day.
☆ World Party Day.
4th
☆ Carrot Day.
☆ Children's Day - Taiwan + Hong Kong.
☆ Cordon Bleu Day.
☆ Independence Day - Senegal.
☆ International Day for Mine Awareness and Assistance in Mine Action.
☆ Peace Day - Angola.
☆ Vitamin C Day.
☆ Walk Around Things Day.
☆ World Rat Day.
5th
☆ Arbor Day (Sikmogil) - South Korea.
☆ Children's Day - Palestine.
☆ Deep Dish Pizza Day.
☆ Go For Broke Day.
☆ National Caramel Day - USA.
☆ Read a Road Map Day.
☆ Star Trek First Contact Day.
6th
☆ Chakri Day - Thailand.
☆ National Beer Day - UK.
☆ New Beer's Eve - USA.
☆ Plan Your Epitaph Day.
☆ Tartan Day.
7th
☆ Beaver Day.
☆ Flag Day - Slovenia.
☆ International Day of Reflection on the 1994 Rwanda Genocide.
☆ Motherhood and Beauty Day - Armenia.
☆ National Beer Day - USA.
☆ No Housework Day.
☆ Sheikh Abeid Amani Karume Day - Tanzania.
☆ Women's Day - Mozambique.
☆ World Health Day.
8th
☆ Buddha's Birthday - Japan.
☆ Draw a Picture of a Bird Day.
☆ International Romani Day.
☆ Trading Cards for Grown Ups Day.
☆ Zoo Lovers Day.
9th
☆ Anniversary of the German Invasion of Denmark - Denmark.
☆ Baghdad Liberation Day - Iraqi Kurdistan.
☆ Bataan Day - Philippines.
☆ Cherish an Antique Day.
☆ Constitution Day - Kosovo.
☆ Day of National Unity - Georgia.
☆ Finnish Language Day.
☆ International Banshtai Tsai Day.
☆ Martyrs' Day - Tunisia.
☆ Name Yourself Day.
☆ National Former Prisoner of War Recognition Day - USA.
☆ Remembrance for Haaken Sigurdsson - Heathenry.
☆ Unicorn Day.
☆ Vimy Ridge Day - Canada.
☆ Winston Churchill Day.
☆ World Konkani Day.
10th
☆ Day of the Builder - Azerbaijan.
☆ Feast of the Third Day of the Writing of the Book of Law - Thelema.
☆ Golfer's Day.
☆ Safety Pin Day.
☆ Siblings Day.
11th
☆ Barbershop Quartet Day.
☆ Juan Santamaria Day - Costa Rica.
☆ International Day of the Liberation of Nazi Concentration Camps.
☆ International Louie Louie Day.
☆ National Cheese Fondue Day - USA.
☆ Pet Day.
☆ Submarine Day.
☆ World Parkinson's Day.
12th
☆ Children's Day - Bolivia + Haiti.
☆ Cosmonautics Day - Russia.
☆ Halifax Day - North Carolina, USA.
☆ International Day of Human Space Flight.
☆ Licorice Day.
☆ National Grilled Cheese Sandwich Day - USA.
☆ National Redemption Day - Liberia.
☆ Walk On Your Wild Side Day.
☆ Yuri's Night.
13th
☆ International FND (Functional Neurological Disease) Awareness Day.
☆ Katyn Memorial Day - Poland.
☆ Scrabble Day.
☆ Teachers' Day - Ecuador.
☆ Thingyan - Burma.
☆ Thomas Jefferson Day - USA.
☆ Unfairly Persecuted Persons Day - Slovakia.
14th
☆ Abushibarei - Ryukyuan.
☆ Ambedkar Jayanti - India.
☆ Black Day - South Korea.
☆ Commemoration of Anfal Genocide Against the Kurds - Iraqi Kurdistan.
☆ Cuckoo Day - UK.
☆ Day of Mologa - Russia.
☆ Day of the Georgian Language.
☆ Dhivehi (Maldivian) Language Day.
☆ Dolphin Day.
☆ Look Up At The Sky Day.
☆ N'Ko Alphabet Day.☆ Pahela Baishakh - Bangladesh.
☆ Pana Sankranti - Odisha, India.
☆ Pan American Day.
☆ St. Tiburtius, Valerian and Maximus Day - Christianity.
☆ Takayama Spring Festival - Japan.
☆ Tamil Puthandu - South Asia.
☆ That Sucks! Day.
☆ Vaisakh - Punjab.
☆ Youth Day - Angola.
15th
☆ Anniversary of the sinking of the Titanic.
☆ Day of the Sun - North Korea.
☆ Hillsborough Disaster Anniversary - UK.
☆ International Microvolunteering Day.
☆ Jackie Robinson Day - USA.
☆ National ASL Day - USA.
☆ National Banana Day - USA.
☆ Take a Wild Guess Day.
☆ Tax Day - USA.
☆ Universal Day of Culture.
☆ World Art Day.
16th
☆ Birthday of Jose de Diego - Puerto Rico.
☆ Birthday of Queen Margrethe II - Denmark.
☆ Eggs Benedict Day.
☆ Emancipation Day - Washington, USA.
☆ Foursquare Day.
☆ Memorial Day for the Victims of the Holocaust - Hungary.
☆ National Healthcare Decisions Day - USA.
☆ Save the Elephant Day.
☆ Wear Your Pyjamas To Work Day.
☆ World Voice Day.
17th
☆ Bat Appreciation Day.
☆ Blah Blah Blah Day.
☆ Evacuation Day - Syria.
☆ FAO Day - Iraq.
☆ Flag Day - American Samoa.
☆ Ford Mustang Day.
☆ Haiku Poetry Day.
☆ Malbec World Day.
☆ National Cheeseball Day - USA.
☆ National Espresso Day - Italy.
☆ Nothing Like a Dame Day.
☆ Women's Day - Gabon.
☆ World Haemophilia Day.
18th
☆ Amateur Radio Day.
☆ Anniversary of the Victory in the Battle of the Ice, 1242 - Russia.
☆ Army Day - Iran.
☆ Columnists Day.
☆ Coma Patients' Day - Poland.
☆ Independence Day - Zimbabwe.
☆ International Day for Monuments and Sites.
☆ Invention Day - Japan.
☆ Lineman Appreciation Day.
☆ Pet Owners' Independence Day.
☆ Pinata Day.
☆ Scouts' Day - Armenia.
☆ World Heritage Day.
19th
☆ Army Day - Brazil.
☆ Beginning of the Independence Movement - Venezuela.
☆ Bicycle Day.
☆ Dutch-American Friendship Day.
☆ Guides' Day - Georgia.
☆ Hanging Out Day.
☆ Holocaust Remembrance Day - Poland.
☆ Indian Day - Brazil.
☆ King Mswati III's Birthday - Swaziland.
☆ Landing of the 33 Patriots Day - Uruguay.
☆ National Garlic Day - USA.
☆ National Health Day - Kiribati.
☆ National Rice Ball Day - USA.
☆ Poetry and the Creative Mind Day.
☆ Primrose Day.
☆ Scouts' Day - Azerbaijan.
20th
☆ 420 Cannabis Culture Day.
☆ Teach Children To Save Day.
☆ UN Chinese Language Day.
☆ Volunteer Recognition Day.
21st
☆ Arbor Day - Kenya.
☆ Bulldogs are Beautiful Day.
☆ Chocolate Covered Cashews Day.
☆ Civil Services Day - India.
☆ Grounation Day - Rastafari.
☆ Heroic Defense of Veracruz - Mexico.
☆ Kang Pan-sok's Birthday - North Korea.
☆ Kartini Day - Indonesia.
☆ Kindergarten Day.
☆ Local Self Government Day - Russia.
☆ National Tea Day - UK.
☆ Queen's Official Birthday - Falkland Islands.
☆ San Jacinto Day - Texas, USA.
☆ Tiradentes' Day - Brazil.
☆ Vietnam Book Day.
☆ World Creativity and Innovation Day.
☆ World Fish Migration Day.
22nd
☆ Denim Day.
☆ Discovery Day - Brazil.
☆ Earth Day.
☆ Holocaust Remembrance Day - Serbia.
☆ International Mother Earth Day.
☆ National Jelly Bean Day - USA.
23rd
☆ Castile and Leon Day - Spain.
☆ Beer Day - Germany.
☆ Independence Day - Conch Republic.
☆ International Pixel-Stained Technopeasant Day.
☆ Jurģi - Latvia.
☆ Khongjom Day - Manipur, India.
☆ Lost Dog Awareness Day.
☆ National Sovereignty and Children's Day - Turkey.
☆ Navy Day - China.
☆ Saint Adalbert of Prague's Day - Czech Republic.
☆ Saint George's Day - England.
☆ Scouts' Day - Mexico.
☆ Talk Like Shakespeare Day.
☆ UN English Language Day.
☆ World Book Day.
24th
☆ Armenian Genocide Remembrance Day.
☆ Children's Day - Zambia.
☆ Concord Day - Niger.
☆ Democracy Day - Nepal.
☆ Fashion Revolution Day.
☆ Firefly Day.
☆ Flag Day - Ireland.
☆ International Sculpture Day.
☆ Kapyong Day - Australia.
☆ Labor Safety Day - Bangladesh.
☆ National Panchayati Raj Day - India.
☆ National Pigs in a Blanket Day - USA.
☆ Republic Day - The Gambia.
☆ St. George's Day - Czech Republic.
☆ St. Mark's Eve - Christianity.
☆ World Day for Laboratory Animals.
25th
☆ Anniversary of First Cabinet of Kurdish Government - Iraqi Kurdistan.
☆ Anzac Day - Australia and New Zealand.
☆ Arbor Day - Germany.
☆ DNA Day.
☆ Feast of Saint Mark - Christianity.
☆ Flag Day - Faroe Islands.
☆ Flag Day - Swaziland.
☆ Freedom Day - Portugal.
☆ Hug a Plumber Day.
☆ Liberation Day - Italy.
☆ Major Rogation - Christianity.
☆ Military Foundation Day - North Korea.
☆ National Zucchini Bread Day - USA.
☆ Parental Alienation Awareness Day.
☆ Red Hat Society Day.
☆ Sinai Liberation Day - Egypt.
☆ World Malaria Day.
☆ World Penguin Day.
26th
☆ Audubon Day.
☆ Confederate Memorial Day - USA.
☆ Day of Remembrance of the Chernobyl Tragedy - Belarus.
☆ Help a Horse Day.
☆ Hug a Friend Day.
☆ Hug an Australian Day.
☆ Lesbian Visibility Day.
☆ Memorial Day of Radiation Accidents and Catastrophes - Russia.
☆ National Pretzel Day - USA.
☆ National Richter Scale Day.
☆ Old Permic Alphabet Day.
☆ Union Day - Tanzania.
☆ World Intellectual Property Day.
27th
☆ Day of Russian Parliamentarism.
☆ Day of Uprising Against Occupation - Slovenia.
☆ Flag Day - Moldova.
☆ Freedom Day / UnFreedom Day - South Africa.
☆ Independence Day - Sierra Leone.
☆ Independence Day - Togo.
☆ Konigsdag - Netherlands.
☆ Marine Mammal Rescue Day.
☆ Morse Code Day.
☆ National Day - Mayotte.
☆ National Prime Rib Day - USA.
☆ National Veterans' Day - Finland.
☆ Tell a Story Day.
☆ World Tapir Day.
28th
☆ Biological Clock Day.
☆ Blueberry Pie Day.
☆ Cubicle Day.
☆ Floralia - Ancient Roman.
☆ Lawyers' Day - Orissa, India.
☆ Mujahideen Victory Day - Afghanistan.
☆ National Day - Sardinia, Italy.
☆ National Heroes Day - Barbados.
☆ Restoration of Sovereignty Day - Japan.
☆ Workers' Memorial Day / World Day for Health and Safety at Work.
29th
☆ Day of Remembrance for All Victims of Chemical Warfare.
☆ International Dance Day.
☆ National Shrimp Scampi Day - USA.
☆ Poya - Sri Lanka.
☆ Shōwa Day - Japan.
☆ World Wish Day.
☆ Zipper Day.
30th
☆ Armed Forces Day - Georgia.
☆ Birthday of the King - Sweden.
☆ Camarón Day - French Foreign Legion.
☆ Children's Day - Mexico.
☆ Consumer Protection Day - Thailand.
☆ Honesty Day - USA.
☆ Independent Bookstore Day.
☆ International Jazz Day.
☆ Martyrs' Day - Pakistan.
☆ National Persian Gulf Day - Iran.
☆ Oatmeal Cookie Day.
☆ Reunification Day - Vietnam.
☆ Russian State Fire Service Day.
☆ Teacher's Day - Paraguay.
☆ Walpurgis Night.
Weeks and Months
☆ Arab American Heritage Month - USA.
☆ Bowel Cancer Awareness Month - UK.
☆ Cancer Control Month - USA.
☆ Confederate History Month - USA.
☆ Donate Life Month - USA.
☆ Financial Literacy Month - USA.
☆ Fresh Florida Tomato Month - USA.
☆ IBS (Irritable Bowel Syndrome) Awareness Month.
☆ Jazz Appreciation Month - USA.
☆ Mathematics and Statistics Awareness Month - USA.
☆ Month of the Resurrection of the Lord - Christianity.
☆ National Grilled Cheese Month - USA.
☆ National Pecan Month - USA.
☆ National Pet Month - UK.
☆ National Poetry Month - USA.
☆ National Poetry Writing Month (NaPoWriMo).
☆ National Prevent Child Abuse Month - USA.
☆ National Soft Pretzel Month - USA.
☆ National Soyfoods Month - USA.
☆ National Volunteer Month - USA.
☆ Parkinson's Disease Awareness Month.
☆ School Library Month - USA.
☆ Sexual Assault Awareness Month.
☆ Stress Awareness Month.
☆ Administrative Professionals' Week. (Last Week)
☆ Crime Victims' Rights Week - USA. (Varies)
☆ European Immunization Week. (Varies)
☆ National Dark-Sky Week - USA. (Week of the New Moon)
☆ National Library Week - USA. (Second Week)
☆ National Park Week - USA. (Varies)
☆ National Public Health Week - USA. (First Week)
☆ National Public Safety Telecommunicators Week - USA. (Second Week)
☆ National Stationery Week.
☆ National Stop Snoring Week - USA.
☆ National Volunteer Week - Canada + USA. (Varies)
☆ Oral, Head and Neck Cancer Awareness Week. (Varies)
☆ Vacation Week In The Americas. (Last Week)
☆ World Allergy Week.
☆ World Homeopathy Awareness Week.
☆ World Immunization Week. (Last Week)
Movable
☆ Confederate Memorial Day - USA.
☆ Day of Dialogue - USA.
☆ Day of Silence - USA.
☆ Drive It Day - UK.
☆ Equal Pay Day - USA.
☆ Feriae Latinae - Ancient Roman.
☆ Global Day of Action on Military Spending.
☆ Global Youth Service Day.
☆ Good Deeds Day.
☆ Hardware Freedom Day.
☆ International Marconi Day. (Saturday closest to Marconi's Birthday - 25th)
☆ National Bookmobile Day - USA. (Wednesday of National Library Week)
☆ National Cleavage Day - South Africa.
☆ National Library Workers Day - USA. (Tuesday of National Library Week)
☆ Opening Day (baseball) - USA.
☆ Pay It Forward Day.
☆ Support Teen Literature Day - USA. (Thursday of National Library Week)
☆ Youth Homelessness Matters Day - Australia.
☆ A drop of water is a grain of gold - Turkmenistan. (First Sunday)
☆ Geologists Day. (First Sunday)
☆ Kanamara Matsuri - Japan. (First Sunday)
☆ National Day of Hope - USA. (First Wednesday)
☆ Tell a Lie Day. (First Thursday)
☆ Walk To Work Day - UK. (First Friday)
☆ DIY Day. (First Saturday)
☆ International Pillow Fight Day. (First Saturday)
☆ Tangible Karma Day. (First Saturday)
☆ Children's Day - Peru. (Second Sunday)
☆ Equal Pay Day. (Second Tuesday)
☆ International Day of Pink. (Second Wednesday)
☆ National D.A.R.E. Day - USA. (Second Thursday)
☆ Fast and Prayer Day - Liberia. (Second Friday)
☆ Air Force Day - Russia. (Second Friday)
☆ Patriots' Day - USA. (Third Monday)
☆ Sechseläuten - Switzerland. (Third Monday)
☆ Administrative Professionals' Day. (Third Wednesday)
☆ Banana Day. (Third Wednesday)
☆ First Day of Summer - Iceland. (First Thursday after April 18th)
☆ College Student Grief Awareness Day. (Third Thursday)
☆ National High Five Day - USA. (Third Thursday)
☆ Auctioneers Day. (Third Saturday)
☆ Husband Appreciation Day. (Third Saturday)
☆ Record Store Day. (Third Saturday)
☆ Pinhole Photography Day. (Last Sunday)
☆ International Guide Dogs Day. (Last Wednesday)
☆ International Noise Awareness Day. (Last Wednesday)
☆ Take Our Daughters and Sons To Work Day. (Fourth Thursday)
☆ Arbor Day - USA. (Last Friday)
☆ Día de la Chupina - Argentina. (Last Friday)
☆ Hairball Awareness Day. (Last Friday)
☆ Children's Day - Colombia. (Last Saturday)
☆ Go Birding Day. (Last Saturday)
☆ National Rebuilding Day - USA. (Last Saturday)
☆ National Sense of Smell Day - USA. (Last Saturday)
☆ Save the Frogs Day. (Last Saturday)
☆ World Tai Chi and Qigong Day. (Last Saturday)
☆ World Veterinary Day. (Last Saturday)
☆ Turkmen Racing Horse Festival - Turkmenistan. (Last Sunday)
☆ Flag Day - Åland Islands, Finland. (Last Sunday)
Check out other months, HERE.
