May 4th is Memorial Day in remembrance for the people who have fought and died during World War II, and wars in general. There is a remembrance gathering in the Nieuwe Kerk in Amsterdam and at the National Monument on the Dam Square in Amsterdam. Throughout the country, two minutes of silence are observed at 8:00 p.m.
May 5th is Liberation Day to mark the end of the occupation by Nazi Germany during World War II. Though this is a national holiday, not everyone has this as a free day every year. This is down to company policy – at least once every 5 years ( 2015, 2020, 2025 etc.) everyone gets the day off from work. Festivals are held at most places in the Netherlands.
Shops may have irregular hours both of these days