Emergency decree in effect in Amsterdam on May 4 and 5

The mayor of Amsterdam has issued an emergency decree on May 4 and 5.

The decree was issued because of the national commemoration day on May 4 of the victims of World War II, and the floating concert, at the occasion of Liberation Day, on the river Amstel, on May 5.

On May 4, there is the national commemoration on Dam Square. At 8pm, 2 minutes of silence are observed in the country.
There will even be no plane departures or landings on Schiphol Airport around 8pm.
Queen Beatrix will lay a wreath at the National Monument on Dam Square, and speeches will be held. The event always attracts thousands of spectators every year.
All traffic to Dam Square will be blocked.

On May 5 the country celebrates Liberation Day, as May 5 was the official end of the war for the Netherlands. One of the big events on that day is the floating (classical) concert on the river Amstel, near the Carré Theatre (close to the Skinny Bridge / Magere Brug). The (festive) concert is free, and always attracts many people.
The concert will be attended, as usual, by the Queen.

The concert starts at 8.30pm, but if you want a good place you might want to be there earlier.