When is National Defense Transportation Day in United States?

May 1, Law Day May 1, Loyalty Day May 1, Lei Day May 2, World Tuna Day May 2, National Day of Prayer May 3, Orthodox Good Friday May 3, Kentucky Oaks May 3, World Press Freedom Day May 4, National Explosive Ordnance Disposal (EOD) Day May 4, Kent State Shootings Remembrance May 4, Rhode Island Independence Day May 4, Orthodox Holy Saturday May 4, Kentucky Derby May 5, Cinco de Mayo May 5, Orthodox Easter May 6, Orthodox Easter Monday May 6, Yom HaShoah May 6, National Nurses Day May 8, Time of Remembrance and Reconciliation for Those Who Lost Their Lives during the Second World War May 8, Truman Day May 8, Victory in Europe Day May 8, World Ovarian Cancer Day May 9, Ascension Day May 10, Confederate Memorial Day May 10, Military Spouse Appreciation Day May 11, World Migratory Bird Day May 12, Mother's Day May 12, International Nurses Day May 14, Primary Election Day May 14, Yom Ha'atzmaut May 15, Peace Officers Memorial Day May 15, International Day of Families May 17, National Defense Transportation Day May 17, World Information Society Day May 18, Armed Forces Day May 18, Preakness Stakes May 19, Pentecost May 20, Whit Monday May 20, World Autoimmune / Autoinflammatory Arthritis Day May 21, World Day for Cultural Diversity for Dialogue and Development May 22, Harvey Milk Day May 22, National Maritime Day May 22, International Day for Biological Diversity May 22, Emergency Medical Services for Children Day May 23, International Day to End Obstetric Fistula May 25, African Liberation Day May 25, National Missing Children's Day May 26, Lag BaOmer May 26, Trinity Sunday May 27, Jefferson Davis' Birthday May 27, Memorial Day May 29, International Day of United Nations Peacekeepers May 30, Corpus Christi May 31, World No Tobacco Day