May 3, 2011 World Press Freedom Day
May 4, 2011 Kent State Shootings Remembrance
May 4, 2011 Rhode Island Independence Day
May 5, 2011 Cinco de Mayo
May 5, 2011 National Day of Prayer
May 6, 2011 Kentucky Oaks
May 6, 2011 National Nurses Day
May 7, 2011 Kentucky Derby
May 7, 2011 National Explosive Ordnance Disposal (EOD) Day
May 8, 2011 Time of Remembrance and Reconciliation for Those Who Lost Their Lives during the Second World War
May 8, 2011 Victory in Europe Day
May 9, 2011 Truman Day observed
May 10, 2011 Yom Ha'atzmaut
May 10, 2011 Confederate Memorial Day
May 12, 2011 International Nurses Day
May 13, 2011 Friday the 13th
May 13, 2011 Native American Day
May 14, 2011 World Migratory Bird Day
May 15, 2011 International Day of Families
May 15, 2011 Peace Officers Memorial Day
May 17, 2011 World Information Society Day
May 17, 2011 Day of Vesak
May 20, 2011 National Defense Transportation Day
May 21, 2011 World Day for Cultural Diversity for Dialogue and Development
May 21, 2011 Armed Forces Day
May 21, 2011 Preakness Stakes
May 22, 2011 International Day for Biological Diversity
May 22, 2011 National Maritime Day
May 22, 2011 Harvey Milk Day
May 25, 2011 African Liberation Day
May 25, 2011 Emergency Medical Services for Children Day
May 25, 2011 National Missing Children's Day
May 29, 2011 International Day of United Nations Peacekeepers
May 30, 2011 Memorial Day
May 30, 2011 Jefferson Davis' Birthday
May 31, 2011 World No Tobacco Day