May 1, 2021 Orthodox Holy Saturday
May 1, 2021 Kentucky Derby
May 1, 2021 National Explosive Ordnance Disposal (EOD) Day
May 2, 2021 Orthodox Easter
May 2, 2021 World Tuna Day
May 3, 2021 Orthodox Easter Monday
May 3, 2021 World Press Freedom Day
May 4, 2021 Kent State Shootings Remembrance
May 4, 2021 Rhode Island Independence Day
May 5, 2021 Cinco de Mayo
May 6, 2021 National Nurses Day
May 6, 2021 National Day of Prayer
May 7, 2021 Truman Day observed
May 7, 2021 Military Spouse Appreciation Day
May 8, 2021 Lailat al-Qadr
May 8, 2021 Time of Remembrance and Reconciliation for Those Who Lost Their Lives during the Second World War
May 8, 2021 World Migratory Bird Day
May 8, 2021 World Ovarian Cancer Day
May 8, 2021 Victory in Europe Day
May 10, 2021 Confederate Memorial Day
May 10, 2021 Confederate Memorial Day
May 12, 2021 International Nurses Day
May 13, 2021 Ascension Day
May 14, 2021 Native American Day
May 15, 2021 International Day of Families
May 15, 2021 Peace Officers Memorial Day
May 15, 2021 Armed Forces Day
May 15, 2021 Preakness Stakes
May 17, 2021 World Information Society Day
May 19, 2021 Emergency Medical Services for Children Day
May 20, 2021 World Autoimmune
May 21, 2021 World Day for Cultural Diversity for Dialogue and Development
May 21, 2021 National Defense Transportation Day
May 22, 2021 International Day for Biological Diversity
May 22, 2021 National Maritime Day
May 22, 2021 Harvey Milk Day
May 23, 2021 International Day to End Obstetric Fistula
May 25, 2021 African Liberation Day
May 25, 2021 National Missing Children's Day
May 26, 2021 Day of Vesak
May 29, 2021 International Day of United Nations Peacekeepers
May 30, 2021 Trinity Sunday
May 31, 2021 World No Tobacco Day
May 31, 2021 Memorial Day
May 31, 2021 Jefferson Davis' Birthday
May 20, 2021 Autoinflammatory Arthritis Day