International Workers' Memorial Day
International Workers' Memorial Day is held on April 28. This event in the third decade of the month april is annual.
International Chernobyl Disaster Remembrance Day on April 26 (A/RES/71/125);
Shōwa Day in Japan on April 29 (昭和の日 is celebrated in Japan to commemorate the birth date of Emperor Showa or Hirohito, the emperor of pre and post-World war II);
Dave Brubeck Day on May 4 (David Warren Brubeck (December 6, 1920 – December 5, 2012) was an American jazz pianist and composer, considered to be one of the foremost exponents of cool jazz. In the United States, May 4 is informally observed as "Dave Brubeck Day". In the format most commonly used in the U.S., May 4 is written "5/4," recalling the time signature of "Take Five", Brubeck's best known recording);