Here is a list of links to strange, fun and unofficial holidays celebrated in May. Links in boldface are profiled on Worldwide Weird Holidays.

May 1

Law Day
CSS Reboot Day
Executive Coaching Day
Global Love Day
International Permaculture Day
Lei Day
Lemonade Day
Loyalty Day
May Day
Mayday for Mutts – 1st Sunday
Motorcycle Mass and Blessing of the Bikes Day
National Chocolate Parfait Day
National Purebred Dog Day
New Homeowners Day
Save the Rhino Day
School Principals’ Day
Silver Star Day
World Laughter Day

May 2

Tuatara Day
International Scurvy Awareness Day
Baby Day
Brothers and Sisters Day
Melanoma Monday
National Play Your Ukulele Day
National Truffle Day
Robert’s Rule of Order Day
World Tuna Day

May 3

National Two Different Colored Shoes Day
Childhood Depression Awareness Day
Garden Meditation Day
National Lumpy Rug Day
National Raspberry Popover Day
National Specially-abled Pets Day
National Teacher Day
National Paranormal Day
Poem on Your Pillow Day
Public Radio Day
World Asthma Day
World Press Freedom Day

May 4

Star Wars Day
Bike To School Day
Bird Day
Great American Grump Out
International Firefighters Day
National Candied Orange Peel Day
National Orange Juice Day
National School Nurse Day
Occupational Safety and Health Professional Day
Petite and Proud Day
Renewal Day
Respect For Chickens Day
World Give Day

May 5

Barbed Wire Festival – 2016
National Cartoonists Day
Cinco de Mayo
International Midwives Day
Martin Z. Mollusk Day
National Children’s Mental Health Awareness Day
National Chocolate Custard Day
National Day of Reason
National Hoagie Day
Oyster Day
Revenge of the Fifth
Totally Chipotle Day

May 6

No Pants Day
International No Diet Day
International Space Day
International Tuba Day
Joseph Brackett Day
Military Spouse Appreciation Day
National Beverage Day
National Crepe Suzette Day
National Nurses Day
National Tourist Appreciation Day
No Homework Day
Provider Appreciation Day

May 7

Mother Ocean Day
Beer Pong Day
Brunch for Lunch Day
Free Comic Book Day
Herb Day
Join Hands Day
Kentucky Derby
National Babysitters Day
National Barrier Awareness Day
National Cosmopolitan Day
National Homebrew Day
National Roast Leg of Lamb Day
National Scrapbooking Day
National Tourism Day
Paste Up Day

May 8

Have a Coke Day
Free Trade Day
Iris Day
Mother’s Day
Mothers at the Wall Day
National Animal Disaster Preparedness Day
National Coconut Cream Pie Day
National Student Nurses Day
No Socks Day
Victory in Europe Day
World Ovarian Cancer Day
World Red Cross and Red Crescent Day

May 9

Vast Wasteland Day
National Butterscotch Brownie Day
National Lost Sock Memorial Day
National Moscato Day
National Women’s Check-Up Day

May 10

Clean Up Your Room Day
Lupus Day
National Shrimp Day

May 11

National Root Canal Appreciation Day
Donate a Day’s Wages to Charity Day
Eat What You Want Day
National Receptionists Day
National Third Shift Workers Day
National Twilight Zone Day

May 12

National Nutty Fudge Day
International Awareness Day
International Chronic Fatigue Syndrome Awareness Day
International Nurses’ Day
Limerick Day
National Fibromyalgia Awareness Day
Odometer Day

May 13

National Blame Someone Else Day – 2016
Fintastic Friday: Giving Sharks a Voice – 2016
Frog Jumping Day
National Apple Pie Day
National Leprechaun Day
Top Gun Day
World Cocktail Day

May 14

Underground America Day
American Indian Day
International Migratory Bird Day
National Buttermilk Biscuit Day
National Dance Like A Chicken Day
National Miniature Golf Day
National Train Day
Stay Up All Night Night
The Stars and Stripes Forever Day
World Belly Dance Day
World Fair Trade Day

May 15

National Slider Day 
Bay to Breakers Race
International Conscientious Objectors Day
International Day of Families
International MPS Awareness Day
National Chocolate Chip Day
National Tuberous Sclerosis Day
Nylon Stockings Day
Peace Officers Memorial Day
Straw Hat Day

May 16

National Sea-Monkey Day
Biographer’s Day
Love a Tree Day
National Mimosa Day
National Piercing Day
National Wear Purple for Peace Day
World Baking Day

May 17

National Walnut Day
International Day Against Homophobia, Biphobia and Transphobia
National Cherry Cobbler Day
National Mushroom Hunting Day
National Pack Rat Day
World Neurofibromatosis Awareness Day
World Telecommunication and Information Society Day

May 18

I Love Reese’s Day
Accounting Day
Emergency Medical Services for Children Day
International Museum Day
Mother Whistler Day
National Cheese Soufflé Day
National Employee Health and Fitness Day
National No Dirty Dishes Day
National Visit Your Relatives Day
Turn Beauty Inside Out Day

May 19

May Ray Day
Boys Club Day
Hummus Day
National Apéritif Day
National Devil’s Food Cake Day
National Hepatitis Testing Day

May 20

International Virtual Assistants Day – 2016
Be a Millionaire Day
Eliza Doolittle Day
Endangered Species Day
Everybody Draw Mohammed Day
National Bike to Work Day
National Defense Transportation Day
National Pizza Party Day
National Quiche Lorraine Day
O. Henry Pun-off Day
Pick Strawberries Day
Weights and Measures Day

May 21

Sister Maria Hummel Day
American Red Cross Founder’s Day
Armed Forces Day
Culture Freedom Day
I Need a Patch for That Day
National Learn to Swim Day
National Memo Day
National Waiters and Waitresses Day
Preakness Stakes
Rapture Party Day
World Whisky Day

May 22

World Goth Day
Canadian Immigrants Day
Harvey Milk Day
International Day for Biological Diversity
National Buy a Musical Instrument Day
National Maritime Day
National Vanilla Pudding Day
Pug Crawl

May 23

World Turtle Day
International Day to End Obstetric Fistula
Lucky Penny Day
National Taffy Day
World Crohn’s and Colitis Day

May 24

International Tiara Day
Brother’s Day
National Escargot Day

May 25

Towel Day
Geek Pride Day
National Brown-Bag-It Day
National Missing Children’s Day
National Senior Health and Fitness Day
National Tap Dance Day
National Wine Day

May 26

Sally Ride Day
National Blueberry Cheesecake Day
World Lindy Hop Day

May 27

National Grape Popsicle Day
Cellophane Tape Day
European Neighbours’ Day
National Title Track Day
National Wig Out Day
Old-Time Player Piano Day
Sunscreen Protection Day
Victoria Day

May 28

Julia Pierpont Day – 2016
Amateur Radio Military Appreciation Day
Amnesty International Day
International Hamburger Day
International Jazz Day
Sierra Club Day

May 29

Put a Pillow on Your Fridge Day
End of the Middle Ages Day
Indianapolis 500
Learn About Composting Day
National Biscuit Day
Neighbor Day
Paper Clip Day
World Digestive Health Day

May 30

Water a Flower Day
Loomis Day
My Bucket’s Got A Hole In It Day
National Mint Julep Day

May 31

Speak in Complete Sentences Day
National Macaroon Day
Save Your Hearing Day
World No Tobacco Day