Cassinga Day in Namibia
Cassinga Day in Namibia is held on May 4. This event in the first decade of the month may is annual.
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);
Peace Officers Memorial Day on May 15 (United States);
Mullivaikkal Remembrance Day on May 18 (Sri Lankan Tamils)