King's Day is held on April 27. Netherlands, Aruba, Curaçao, Sint Maarten. Celebrated on April 26 if April 27 falls on a Sunday. This event in the third decade of the month april is annual.
Dutch-American Friendship Day on April 19 (United States);
Remembrance Day in the Netherlands on May 4 (it was observed for the first time on May 4, 1946. Every year, people dedicate two minutes of silence at 8pm (local time) on May 4 to pay their respects to soldiers and civilians who died during World War II, as well as other military conflicts and peace-keeping missions);
Liberation Day in the Netherlands on May 5 (Soon after the Second World War, it was decided that Liberation Day should be held on 5 May, the date of the German army’s defeat);
Mother’s Day on May 9 (Anguilla, Antigua and Barbuda, Aruba, Australia, Austria, Bahamas, Bangladesh, Barbados, Belgium, Belize, Bermuda, Bhutan, Bonaire, Botswana, Brazil, Brunei, Canada, Cambodia, Cayman Islands, Central African Republic, Chad, Chile, China, Colombia, Congo, Dem. Rep., Congo, Rep., Cote d'Ivoire, Croatia, Cuba, Curaçao, Cyprus, Czech Republic, Denmark, Dominica, Ecuador, Equatorial Guinea, Estonia, Ethiopia, Faroe Islands, Fiji, Finland, Germany, Gabon, Gambia, Greenland, Ghana, Greece, Grenada, Guyana, Honduras, Hong Kong, Iceland, India, Italy, Jamaica, Japan, Kenya, Latvia, Liberia, Liechtenstein, Macau, Malaysia, Malta, Myanmar, Namibia, Netherlands, New Zealand, Pakistan, Papua New Guinea, Peru, Philippines, Puerto Rico, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Samoa, Singapore, Sint Maarten, Slovakia, South Africa, Sri Lanka, Suriname, Switzerland, Taiwan, Tanzania, Tonga, Trinidad and Tobago, Turkey, Uganda, Ukraine, United States, Uruguay, Vietnam, Venezuela, Zambia, Zimbabwe);
Christ's Ascension on May 13 (or Kristi Himmelfartsdag in Norway);
Whit Monday on May 24 (celebrated on the day after Pentecost);
Grandparents and Great-Grandparents Day in Netherlands on June 4 (Opa en Oma Dag)