| National Day of Life, Peace and Justice | |  |
| Make Up Your Own Holiday Day | | |
| Prince Jonah Kuhio Kalanianaole Day | | |
| Martyrs' Day | | |
| Purple Day | | |
| National Spinach Day | | |
| National Nougat Day | | |
| National Little Red Wagon Day | | |
| Manatee Appreciation Day | | |
| Laylat al-Qadr (Night of Power) | | |
| Laylat al-Qadr | | |
| Wear A Hat Day | | |
| American Red Cross Giving Day | | |
| Armed Forces' Day | | |
| National Scribble Day | | |
| National Joe Day | | |
| National Spanish Paella Day | | |
| International Whisk(e)y Day | | |
| World Theatre Day | | |
| Quirky Country Music Song Titles Day | | |
| Children's Picture Book Day | | |
| Eat an Eskimo Pie Day | | |
| National Black Forest Cake Day | | |
| National Something On a Stick Day | | |
| Weed Appreciation Day | | |
| National Triglycerides Day | | |
| Respect Your Cat Day | | |
| Youth Day | | |
| Martyrs' Day | | |
| Smoke and Mirrors Day | | |
| Commemoration of Boganda | | |
| National Vietnam War Veterans Day | | |
| National Mom and Pop Business Owners Day | | |
| National Lemon Chiffon Cake Day | | |
| Earth Hour | | |
| World Piano Day | | |
| Nano Days | | |
| International Mermaid Day | | |
| Niagara Falls Runs Dry Day | | |
| Spiritual Baptist Liberation Day | | |
| National Doctors' Day | | |
| National Take a Walk in the Park Day | | |
| National I Am in Control Day | | |
| National Pencil Day | | |
| National Turkey Neck Soup Day | | |
| National Virtual Vacation Day | | |
| Ugadi | | |
| Eid al-Fitr (End of Ramadan) | | |
| Mother's Day | | |
| Mothering Sunday | | |
| National Neighbor Day | | |
| Pretzel Sunday | | |
| Transfer Day | | |
| Freedom Day | | |
| Micronesia Culture Day (Chuuk & Pohnpei) | | |
| National Crayon Day | | |
| National Tater Day | | |
| National Bunsen Burner Day | | |
| National Clams on the Half Shell Day | | |
| National Prom Day | | |
| Eid al-Fitr (End of Ramadan) | | |
| Seward's Day | | |
| César Chávez Day | | |
| Hari Raya Puasa | | |
| World Backup Day | | |
| National Farm Workers Day | | |
| Eiffel Tower Day | | |
| National Cream Cheese Frosting Day | | |
| National Day | | |
| Investiture of the Captains Regent | | |
| April Fool's Day | | |
| National Poetry Month | | |
| National One Cent Day | | |
| National Sourdough Bread Day | | |
| SAAM Day of Action | | |
| Eid al-Fitr (End of Ramadan) Holiday | | |
| National Atheist Day | | |
| Sexual Assault Awareness Month | | |
| World Sarcoidosis Awareness Month | | |
| Fun Day | | |
| International Fun At Work Day | | |
| Reading Is Funny Day | | |
| National Garden Month | | |
| Summer Tire Changeover Month | | |
| National Soft Pretzel Month | | |
| National Afternoon Tea Month | | |
| National Autism Awareness Month | | |
| National Month Of Hope | | |
| National Humor Month | | |
| National Safe Digging Month | | |
| Adopt A Ferret Month | | |
| National Pecan Month | | |
| National Fresh Celery Month | | |
| National Brunch Month | | |
| International Guitar Month | | |
| Active Dog Month | | |
| National Decorating Month | | |
| Month Of The Military Child | | |
| National Straw Hat Month | | |
| National Welding Month | | |
| National Canine Fitness Month | | |
| Limb Loss And Limb Difference Awareness Month | | |
| National Cannabis Awareness Month | | |
| National Soy Foods Month | | |
| Stress Awareness Month | | |
| National Jazz Appreciation Month | | |
| National Child Abuse Awareness Month | | |
| Day of the Veterans | | |
| Union Day of Belarus and Russia | | |
| International Children's Book Day | | |
| National Reconciliation Day | | |
| National Peanut Butter and Jelly Day | | |
| National Ferret Day | | |
| National Walking Day | | |
| Childhelp National Day of Hope | | |
| Pascua Florida Day | | |
| World Autism Awareness Day | | |
| Eid al-Fitr (End of Ramadan) Holiday | | |
