National Kids and Pets Day
Remember Your First Kiss Day
Hug A Friend Day
Static Cling Day
Secretary's Tea Day
Hug an Australian DayBuccaneer Days Festival begins (Corpus Christi , TX, 1938) - annual 24-day celebration with a pirate theme as a celebration based on the history and legend of the days of long ago when pirate ships sailed the waters of the Gulf and preyed on merchantmen
Read Me Day
International Azalea Festival
National Richter Scale Day: the Richter scale (from 1 to 10) is the creation of Charles Richter and Beno Gutenberg, both of the California Institute of Technology (CalTech) as an earthquake magnitude rating scale,1935
World Intellectual Property Day (UN, 1970): to increase people’s awareness and understanding of intellectual property (IP)
Birthday of John James Audubon (Jean-Jacques Audubon) (1785-1851), a French-American ornithologist, naturalist, hunter, and painter and namesake of the Audubon Society. In 1905, the National Audubon Society was incorporated and named in his honor. Its mission "is to conserve and restore natural ecosystems, focusing on birds, other wildlife, and their habitats for the benefit of humanity and the earth's biological diversity."
International Day of Chernobyl, April 1986, was a nuclear accident that occurred on this date in 1986 at the Chernobyl Nuclear Power Plant in the Ukrainian SSR (now Ukraine). An explosion and fire released large quantities of radioactive contamination into the atmosphere, which spread over much of Western Russia and Europe. It is considered the worst nuclear power plant accident in history, and is one of only two classified as a level 7 event on the International Nuclear Event Scale.
The Salk polio vaccine field trials, involving 1.8 million children, began on this date in 1954, at the Franklin Sherman Elementary School in McLean, Virginia. By April 12, 1955, researchers announced the vaccine was safe and effective and it quickly became a standard part of childhood immunizations in America and helped wipe out the highly contagious disease in the Western Hemisphere.
Easter Tuesday (Australia)
Christian Feast Day honoring various saints
St. Marcellinus' Day
Last day of Passover/Pesach
The Day of Ashura/Tenth Day (عاشوراء), which means tenth in Arabic, is on the 10th day of Muharram in the Islamic calendar and marks the climax of the Remembrance of Muharram.
Vallenato Legend Festival (Valledupar, Colombia) is one of the most important musical festivals in Colombia since 1968
National Union Day (United Republic of Tanzania, 1964)
Day of Remembrance of the Chernobyl tragedy (Belarus)
Cape Henry Day (Virginia)
Confederate Memorial Day (FL & GA)
(Source: history.com & Wikipedia; photo credit: pretzel, weblogs.sun-sentinel.com; kiss, musiciansatlas.com; teacup, dandonnelly.wordpress.com; azaleas, art.com; Indonesia quake, Richter Scale, esrf.eu; Audubon bird painting of an eagle, antiqueprintsblog.blogspot.com; The nuclear reactor after the disaster. Reactor 4 (center). Turbine building (lower left). Reactor 3 (center right), Wikipedia; Jonas Salk with vaccine, americaninvetors.blogspot.com; Vallenato musicians, vivatravelguides.com; IP Day, wipo.int)